Electrification readiness against the spare amps you have
This is not NEC 220.82 run again. Take spare amps from the load calculator (or from an electrician), then add the new 240 V demand of a heat pump, an electric dryer placeholder, and an EVSE at 125%. The question is whether those three fit in the spare you already have.
Spare − newnot a restamp of 220.82Heat pump VA ÷ 240, plus 24 A if the dryer is electric, plus EVSE current × 1.25. Compared to spare amps you bring from the load calculator. Illustrative, not a stamp.
Type spare amps from the load calculator, heat-pump nameplate VA, gas vs electric dryer, and EVSE amps.
A 6,000 VA heat pump is 25 A at 240 V, an electric dryer is a 24 A placeholder here, a 32 A charger is 40 A at 125%. Together that is 89 A of new demand.
If you only had 40 A spare, this is a service or load-management conversation, not a shopping list. Live work is not DIY.
Spare, then the three new loads
Spare comes from the load calculator. This will not restamp 220.82. Nothing is emailed.
Heat pump VA/240 + electric dryer 24 A placeholder + EVSE × 1.25, compared to spare amps you typed. Not NEC 220.82 restated. Live work is not DIY. HyreElectrical does not perform electrical work.
Electrification does not use up your amps. It uses up your diversity
The reason a house that coped with a hundred years of appliances suddenly cannot cope has almost nothing to do with the size of the new loads and almost everything to do with how long they run.
Diversity is the assumption the whole system rests on. A service is not sized for every appliance at full draw, because they do not coincide.
The Code writes this into the arithmetic: NEC 220.82 permits the general load to be “The general calculated load shall be not less than 100 percent of the first 10 kVA plus 40 percent of the remainder of the following loads”.
Sixty percent of everything above the first 10 kVA simply does not count.
That assumption is a statement about behavior. Kettles boil, toasters pop, microwaves finish, showers end. Each load is large and brief, arriving at random, so the chance of many peaking together is small. The demand factor is the codified version of that observation.
The new loads behave differently. A heat pump runs for hours when it is cold. A heat pump water heater runs on a schedule. A car charges all night.
An induction hob is brief, but it is brief during the same evening hours as the heating. These are long, steady and correlated rather than short and random.
Correlated is the word that matters. They coincide because they are all driven by the same events — the temperature dropping, everybody coming home. Diversity is not a fixed property of a building; it is a property of how the building is used, and electrification changes how the building is used.
Which is the honest case for a service upgrade, and a far better one than "your panel is old".
If somebody is recommending a larger service, the question that tests the recommendation is which loads they expect to coincide, and for how long. A good answer names the winter evening. A weak answer names the nameplate sum.
And the honest case against it is that correlation can sometimes be engineered away. If the charger yields to the heat pump, the two never coincide by design. That is the subject of the next section, and it is the biggest single lever in this whole area.
The loads can be made to take turns
Making loads take turns is the part of electrification that has changed most in the last few years, and the part least likely to be raised by somebody quoting a panel.
Illustrative, said here rather than in a footnote. The direction is reliable; the size depends entirely on the equipment installed and the household’s pattern.The mechanism for the charging bars is NEC 625.42(A) and NEC 625.42(B), 2023 edition. The magnitudes are ours.
The Code sentence that makes it count. NEC 625.42(A): “Where an EMS in accordance with 750.30 provides load management of EVSE, the maximum equipment load on a service and feeder shall be the maximum load permitted by the EMS.”
The managed maximum, not the nameplate, is what the service calculation carries. That is a real engineering allowance, not a promise from a salesperson.
And the simpler version. NEC 625.42(B): “EVSE with restricted access to an ampere adjusting means complying with 750.30(C) shall be permitted.” Commissioning the equipment at a lower current, where the occupant cannot raise it, produces a smaller load for calculation purposes.
Why charging is the easiest load to manage. It is the only large domestic load that nobody notices being deferred. Nobody is standing over the car.
A charger that pauses for forty minutes while the oven and the dryer run finishes at 4am instead of 3am, and the outcome — a full car in the morning — is identical.
Compare that with the others. Deferring space heating is noticed immediately and is not a lever most households will accept. Deferring water heating is noticeable only if you get the timing wrong.
Cooking cannot be deferred at all. The order of what to manage is set by what the household will tolerate, and it happens to start with the largest and most flexible load.
What we deliberately do not quote here. NEC Article 702 (optional standby systems) and Article 705 (interconnected power production sources, including the busbar sizing allowance often called the "120 percent rule") are directly relevant to generator and battery work.
We did not retrieve verbatim text for either on the retrieved date, so no numeric rule from them is quoted anywhere on this site. Ask the electrician which article they are working to.
The 625 allowance above is EV-specific and verified; we are not going to generalise it into a rule about battery systems or standby equipment that we did not verify.
The order you do these in changes the answer
Each project changes the capacity available to the next one, and two of them release capacity rather than consuming it. Nobody plans this as a sequence, and the sequence is most of the economics.
Project
Effect on the calculated load
What it enables next
The trap
Insulation, air sealing, windows
Reduces it — smaller heating and cooling equipment for the same comfort.
Everything. A smaller heat pump is a smaller load and often a smaller circuit.
It is invisible, so it is always the project that gets postponed in favor of equipment you can point at.
Heat pump replacing a gas furnace
Adds the largest single new load in most houses. Under NEC 220.82(C) heating and cooling count as the largest of six selections, not the sum, so replacing a furnace where an air conditioner already exists is not purely additive.
Nothing directly, but it is usually the project that determines whether the service holds.
Electric strip backup. Under 220.82(C)(3) the compressor counts at 100 percent with 65 percent of the supplemental heat — strips can dominate the calculation while running for a handful of hours a year.
Heat pump water heater replacing gas
Adds a modest load, and one of the easiest to shift off the evening peak.
Little directly. But as a scheduled load it is a good candidate for management.
Placement. These need air volume and they cool the space they are in, which is fine in a garage and less fine in a small interior closet.
Induction hob replacing gas
Adds a 240 V circuit. Note NEC Table 220.55, Column C: in the standard calculation a single range not over 12 kW is taken as 8 kW of demand, which is a much smaller number than the nameplate.
Nothing. It is usually done for cooking, not for energy.
Assuming the nameplate is the calculated load. On this one appliance the Code’s own table says otherwise, and it says so by a third.
EV charging
Adds a continuous load at 125 percent — unless managed under NEC 625.42(A), in which case the managed maximum is used.
Nothing, but it is the most flexible load in the house and therefore the best one to manage.
Buying the largest available charger by default. A larger charger is a larger circuit, a larger calculated load, and frequently no earlier finish time overnight.
Removing the last gas appliance
Removes a fixed gas standing charge from the bill — a real saving that has nothing to do with amperes.
Nothing electrical.
Doing it before the rest of the electrification is affordable. A half-electrified house pays for two connections.
Our own framing of how the projects interact. The Code citations are quoted from the sources; the sequencing argument is ours. Adoption and amendment of the National Electrical Code is local.
A state or city may be on an older edition, may amend it, and may add rules of its own. Confirm the adopted edition and the amendments with the authority having jurisdiction before relying on any code figure here.
Where the "spare amps" number this tool asks for actually comes from
HyreElectrical will not invent the spare-amps figure, and the reason is worth understanding, because the wrong version of it is the most common error in the whole subject.
It is not the number on the main breaker. A 200 A main tells you the ceiling, not the headroom. Every existing appliance in the house is already claiming part of that, and the spare is what is left after the calculation, not the rating itself.
It is not the sum of the breakers either. Adding up branch breakers in a panel routinely exceeds the main by a wide margin and is supposed to. Branch breakers protect their conductors; they do not describe demand.
It is service rating minus calculated load.
The calculated load comes from running an article of the Code over your nameplates — NEC 220.82 for the optional whole-house method, or NEC 220.83 where the question is specifically “This section shall be permitted to be used to determine if the existing service or feeder is of sufficient capacity to serve additional loads.”
And NEC 220.83 is usually the right article here, because it was written for exactly this: an existing house asking whether it can take an addition.
Its demand factors are slightly harsher — the first 8 kVA at 100 percent rather than 10 kVA — so it lands a little higher, which is why two competent people can produce two different figures without either being wrong.
Where to get a number you can rely on. From an electrician who has seen the house and will put it in writing.
The load calculator on this site produces the shape of the answer so you can tell whether a proposal is plausible; it is not the document. Nothing on this site is a stamped load calculation, a design, or a permit document.
A load calculation that an inspector accepts is produced by someone who has seen the building and signs for it.
And what to do if the honest answer is "nobody knows". Type zero. A zero here produces a conservative result and an obvious next step, which is better than a guessed number producing a confident wrong one.
What to ask before committing to any electrification work
Six questions that separate a designed electrification plan from a sequence of separately-sold boxes.
Which article was the load calculation run under, and for what scope?
The whole-house optional method in NEC 220.82, or the existing-dwelling check in NEC 220.83? They answer different questions and give different numbers.
Does the calculation still fail with the new load managed?
NEC 625.42(A) permits the managed maximum to be the figure used. If a service upgrade is proposed, this question should already have been asked and answered.
Has the whole plan been calculated, or only this project?
Three projects passing individually can fail together. Ask for the calculation with all the intended loads in it, even the ones two years away, because the answer determines whether the service work is done once or twice.
Does the panel have positions, and adjacent ones?
Every 240 V addition needs two adjacent positions. Capacity and room are separate constraints, and running out of room is usually the cheaper problem — a subpanel does not involve the utility.
What does the heat pump proposal assume about backup heat?
Under 220.82(C)(3) the compressor counts at 100 percent with 65 percent of the supplemental electric heat. Strip heaters that run for a few hours a year can be the line that decides the service size, which is a real argument for sizing and controlling them carefully.
Is the service below the modern minimum, independently of all this?
NEC 230.79(C): “For a one-family dwelling, the service disconnecting means shall have a rating of not less than 100 amperes, 3-wire.” A 60 A service is below the Code’s floor for new work: a reason on its own, not an electrification argument.
A plan that begins with the panel
Sometimes correct, often the most expensive possible starting point. The efficiency work that shrinks the equipment, and the management that shrinks the calculated load, both come first in logic even when they come second in enthusiasm.
On money, briefly and accurately
We publish no prices. There is no national average price for a panel upgrade, a service change, an EVSE circuit or a rewire on this site, because we hold no dataset of bids and the figures that circulate in roundups come from lead-generation sites with unpublished methods.
How many US homes would be adding cooling from scratch, and the NEC 220.83 arithmetic that applies to that retrofit, is homes without central air conditioning.
The federal credit, stated as the IRS states it. “The credit is allowed for qualifying property placed in service on or after Jan. 1, 2023, and before December 31, 2025.”
And on electrical work specifically: “Costs of electrical components needed to support residential energy property, including panelboards, sub-panelboards, branch circuits, and feeders, also qualify for the credit if they meet the National Electric Code and have a capacity of 200 amps or more. There is a limit of $600 per item.”
Which means, in 2026: On the retrieved date the IRS states the credit window as ending before 31 December 2025. Property placed in service after that date is outside the window described.
Any page, quote or salesperson still offering "the federal panel credit" as a live discount in 2026 is describing a window the IRS page no longer describes as open.
Confirm your own position with the IRS page or a tax professional; we are neither.
Running cost is the number that is genuinely knowable.Electricity prices vary enormously by state — EIA’s June 2026 figures run from 13.37¢/kWh to 52.72¢/kWh, against a US average of 18.34¢/kWh. Any claim about what electrification will cost to run that does not start from your own rate is not a claim about your house.
And the standing charge nobody models. Keeping one gas appliance keeps the gas connection and its fixed monthly charge. That is a real and easily overlooked line, and it is the reason a partly electrified house sometimes saves less than expected.
What this tool cannot do
The readiness tool does not calculate your spare capacity. It compares new demand against a figure you supply, so it inherits whatever that figure is worth.
Nothing on this site is a stamped load calculation, a design, or a permit document. A load calculation that an inspector accepts is produced by someone who has seen the building and signs for it.
It is not the Code’s method run again. It is deliberately simpler than NEC 220.82, and it is not NEC 220.83 either. It answers one narrow question about fit.
The dryer figure is a planning placeholder, not your nameplate. Any real calculation uses the plate on your machine.
It cannot see the panel. Positions, adjacency, busbar rating and what the label permits are all invisible to it and any of them can stop a project that passes here.
It knows nothing about your utility or your jurisdiction. Adoption and amendment of the National Electrical Code is local. A state or city may be on an older edition, may amend it, and may add rules of its own.
Confirm the adopted edition and the amendments with the authority having jurisdiction before relying on any code figure here. Some utilities have their own requirements for large new loads, and those are asked about locally.
And it is not a design. HyreElectrical does not perform, supervise or warrant electrical work, does not open panels, and does not pull permits. HyreElectrical holds no dataset of bids, invoices, inspections or jobs. No figure on this site is our own measurement of the market.
How this calculator works
The calculator converts three possible new loads to amps at 240 V and compares the sum to spare amps you typed:
heat pump A = nameplate VA / 240
dryer A = 24 if electric, else 0
EVSE A = current you typed × 1.25
need = heat pump A + dryer A + EVSE A
talk = spare − need (overshoot or leftover)
On a 6,000 VA heat pump (25 A), an electric dryer (24 A placeholder) and a 32 A EVSE (40 A at 125%), need is 89 A. Against 40 A spare, that overshoots by 49 A.
Against 100 A spare, 11 A still shows as leftover. Both sentences are illustrative. Neither is a stamped load calculation, and neither is a restamp of the optional calculation in 220.82. That work already lives on the load calculator.
If spare is 0 and the new loads are 0, you will see a leftover of 0 A. That is "you typed nothing," not a pass. Type the spare from the load calculator before you trust the talk line.
What each input means
Inputs on this tool, in the order they appear on the form.
Input
What it is actually asking
Spare amps
What you have left on the existing service after the house-shaped demand. From the load calculator "against existing service," or from an electrician. 0 means no spare. It does not mean unknown.
Heat pump VA
Nameplate volt-amperes. Divided by 240 to get amps on this form. Use the larger of heating and cooling if both are on the plate, as you would on the load calculator. 0 if you are not adding one.
Dryer
Gas is 0 A. Electric is a 24 A placeholder, not your nameplate. If the plate is very different, put the real VA in the load calculator rather than arguing with 24 here.
EVSE current
Amps at 240 V the charger will draw, then ×1.25 as a continuous load. 0 if none. Same 125% as the circuit estimator.
Worked examples
Including one where the naive answer misleads, which is the example most calculators leave out.
A heat pump only, on spare you actually have
Spare 40 A from the load calculator, heat pump 6,000 VA, dryer gas, EVSE 0. Need = 6,000 / 240 = 25 A. Talk: 15 A still spare on these figures.
That leftover is not a permit, and it is not room for the EV you have not typed yet.
It is a reason to keep going with an electrician rather than to assume 40 A spare is a 40 A shopping budget.
Heat pump, electric dryer and a 32 A charger
Spare 40 A, heat pump 6,000 VA (25 A), dryer electric (24 A), EVSE 32 A × 1.25 = 40 A. Need 89 A. Talk: these three loads overshoot the spare you typed by 49 A.
That is a service or load-management conversation, not a cart with three appliances in it. Lowering the EVSE to 16 A (20 A at 125%) is one of the things an electrician can price. This page will not pick it for you.
The one where "the panel is 200 A" misleads
A 200 A label on the dead front, spare typed as 200 because that is the number on the door, then heat pump + dryer + EVSE added as if the house currently draws nothing.
The naive answer is plenty of room. The load calculator is there to stop that. Existing range, HVAC, water heater and general load already occupy most of a 100 A or 200 A service.
Spare is the leftover after that, not the rating printed on the box. Type the leftover. If you have not run the load calculator, this page is early.
What changes the result
EVSE current is the lever that most often changes the talk line, because of the 125% multiplier. 24 A of charger current is 30 A of demand. 32 A is 40 A. 48 A is 60 A.
Dropping from 32 A to 24 A is 10 A back, which is sometimes the difference between overshoot and leftover on a tight service. It is also a slower charge. The EV selector is where miles and hours say whether that slower charge still covers the day.
Switching dryer from gas to electric adds a flat 24 A on this form. That is a lot, on a 100 A service that already has a heat pump. Keeping a gas dryer is a real electrification choice, not a moral failure, and this tool will show it as 0 A.
Heat pump VA moves one-for-one with the plate. A 3,600 VA unit is 15 A. A 12,000 VA unit is 50 A. Use the plate, not a "3-ton" rule of thumb we would have to invent.
Local considerations
Which edition of the NEC your jurisdiction adopted, whether load management is accepted in place of a service upgrade, and what the utility requires for a service change are local.
This page will not list them by state. The spare figure is yours. The new demand is nameplates and a 24 A dryer placeholder. The decision is the electrician, against the adopted code, not this form.
When not to use this
Do not use this as a stamped load calculation, a permit, or a reason to open the panel. It is not 220.82. It cannot see existing loads you left out of the spare number, a heat pump whose nameplate is in a different unit, or a panel with no spaces.
Do not type the service rating as spare. Spare is leftover. The load calculator exists so you do not have to guess it.
Do not use a leftover here as proof you can add all three tomorrow. Load management, diversity and the adopted edition belong with a licensed electrician.
HyreElectrical does not perform electrical work. Matching is still being built. The inquiry form is not a booking.
Can my panel handle a heat pump, a dryer and an EV charger?
Only against spare capacity calculated for this house. This tool subtracts new 240 V demand from the spare amps you type; it will not invent the spare. Run the load calculator first, or use a figure an electrician gave you. "The panel says 200 A" is the box's rating, not the spare.
Is this a NEC 220.82 load calculation?
No. NEC 220.82 is the optional whole-house calculation, and this site's load calculator already follows its shape: first 10 kVA at 100%, the rest at 40%, HVAC at 100%, EV charging at 125%. This page only asks whether three new 240 V loads fit in the spare you bring.
Why is the electric dryer 24 A?
It is a planning placeholder for a typical 30 A, 240 V dryer circuit at 80%, not your nameplate. With the dryer's plate figure, use this as a coarse check, then enter the real VA in the load calculator. A gas dryer stays at 0 A because it adds no 240 V demand.
Why is the EV charger multiplied by 1.25?
Because a charger is a continuous load: its circuit is planned at 125% of the current you set. A 32 A charger is 40 A of demand on this form, the same rule the circuit estimator uses. Reading 32 as 32 is how people conclude a 200 A panel has room it lacks.
What is spare amps?
Existing service amps minus the calculated demand from the load calculator, or a spare figure an electrician already wrote down. If the calculation says the house is already over its service, type 0. An empty box counts as 0, which means no spare, not unknown.
The result says I still have spare. Can I add all three?
Not from this page. The leftover is illustrative. Diversity, the adopted NEC edition, load management, and whether those three loads actually coincide are the electrician calculation. A positive leftover here is a reason to have that conversation, not a permit.
The result overshoots. Is that a service upgrade?
It is a service or load-management conversation. Whole-house load control, a lower EVSE current, keeping the dryer on gas, or a service change are different jobs. This tool will not pick one. It will not open the panel either.
Do I still need the load calculator if I use this?
Yes. This page is downstream of it. Without a house-shaped demand number, spare is a guess, and a guess plus three new 240 V loads is how "we electrified the house" becomes a dark house on a cold evening.
Does panel space matter as well as amps?
Yes, independently. A 200 A panel can be full. Count spaces on the panel space checker. Heat pump, dryer and EVSE are usually three separate 240 V two-pole breakers. Spare amps with no spaces is still a project.
Does HyreElectrical do electrification work?
No. HyreElectrical does not perform electrical work, size heat pumps, or sell chargers. Matching is still being built. The inquiry form is not a booking.
Sources and methodology
Figures dated 26 August 2026. Last reviewed .
NFPA 70, National Electrical Code, Article 220 (National Fire Protection Association, retrieved 2026-08-26. Cited as the model code. The load calculator on this site is shaped like the optional calculation. This page is not a reprint of 220.82. Confirm the edition your jurisdiction adopted.)
Charging electric vehicles at home (U.S. Department of Energy, Alternative Fuels Data Center, retrieved 2026-08-26. Cited for home charging as a household electrical load. Current and 125% live on the circuit estimator, not in an AFDC amp table.)
Home electrical safety guidance (Electrical Safety Foundation International, retrieved 2026-08-26. Cited for the standing rule that service and panel work are not DIY.)