Residential Electrical Panel Upgrade Checker

Do I need an electrical panel upgrade? Checks whether your existing panel can take an EV charger, heat pump or induction range, using the real code load-calculation methods rather than a rule of thumb.

Your electrical panel

What size is your main breaker?The number printed on the big switch at the top of the panel

Main breaker rating i

Service type

Which NEC edition does your area use? iAdoption is state by state — this changes the maths, not just the wording

Supply voltage

Advanced / Custom Input — my panel

I know my capacity in kVA instead iOverrides the amps above. Leave at 0 to use the breaker rating.

kVA

Usable share of the mainSome authorities want a margin left unused.

About the home

How big is your home?Heated living space — skip the garage, porch and unfinished basement

sq ft

Area unit

Kitchen small-appliance circuitsThe code requires at least two

nos

Laundry circuits

nos

Lighting pointsRoughly how many light fittings in the house

nos

Power points (10 A socket outlets)

nos

Total lighting loadAdd up the fittings, or leave the estimate

Socket circuits (rings)32 A ring finals

nos

Socket circuits (radials)20 A radial finals

nos

Electric showerNo diversity is allowed on this — it counts in full

Advanced / Custom Input — about the home

I already have a general-load figureFrom a survey or an earlier calculation. Replaces the area and circuit maths.

kVA

What you already have

These start at typical values. Change any that do not match, or set one to 0 if you do not have it.

Electric range / ovenThe cooker, not a separate cooktop

Electric clothes dryerLeave at 0 for a gas dryer

Electric water heaterTank or tankless — use the nameplate

Dishwasher

Waste disposal

Built-in microwaveOnly if it is wired in, not plugged in

Well pump / pool pump

Existing air conditioningRunning watts from the nameplate

Existing electric space heatingBaseboards or a furnace heat strip

Advanced / Custom Input — existing loads

Enter my total existing load insteadReplaces every appliance figure above. Leave at 0 to add them up one by one.

What you want to add

EV chargerThe circuit breaker size the charger needs

Charger current i

How many chargers?

nos

Heat pump (compressor)Running watts of the outdoor unit

Heat pump backup heat stripThe electric element that helps on cold days

Is the backup heat locked out when the compressor runs? i

Induction range / cooktop

How is the electric heating controlled? i

Advanced / Custom Input — new loads

Any other new load to addCounted in full, on top of the charger and heat pump above.

Load management

Fit a load-management device? iIt throttles the charger when the house is busy, instead of upgrading the panel

Charger is throttled down to

Advanced / Custom Input — load management

My device caps the whole site atA whole-site limiter rather than a charger-only throttle. Leave at 0 if it only controls the charger.

Advanced / Custom Input — override any assumption

The metered method — NEC 220.87

If you can get your highest demand over the last 12 months from the utility or a smart meter, this is the most accurate method there is — and it usually gives far more headroom than a calculation from scratch. Leave it at 0 to skip it.

Highest demand in the last 12 months i

Demand multiplier

NEC demand factors

General lighting allowance i

VA/ft²

First demand tier at 100% i

Remainder demand factor

VA per required circuit

Range demand (Table 220.55) i

EVSE minimum load i

EV continuous-load factor i

Air conditioning factor

Supplemental heat factor

Canadian Electrical Code — CSA C22.1 Section 8

Basic load, first 90 m² i

Each further 90 m²

Code minimum, 80 m² or more i

Code minimum, under 80 m²

Range base allowance i

Range, amount over 12 kW

Space heating over 10 kW i

Other loads over 1500 W

Germany — DIN 18015-1 Annex A

Base demand, no electric water heating i

Base demand, with electric water heating

Heat pump under §14a EnWG i

Wallbox with load management i

General IEC estimate — conservative allowances

This country’s own diversity table is not encoded yet, so these deliberately cautious allowances are used instead. They will tend to over-estimate. Change any of them if you know your local figures.

Lighting

Socket circuits

Cooking

Other appliances

BS 7671 diversity — IET On-Site Guide Appendix A

Lighting diversity

Socket circuits after the largest i

Cooker — first slice at 100%

Cooker — remainder

Add if the cooker unit has a socket

Space heating — first slice at 100%

Space heating — remainder i

AS/NZS 3000 Appendix C — Table C1 column 2

Lighting — first 20 points

Lighting — each further 20 points

Power points — first 20

Power points — each further 20

Ranges and cooking i

Fixed heating and air conditioning i

Water heating

Your own parameter

Anything the fields above do not cover — a workshop sub-feed, a hot tub, a grow tent, a second kitchen. Positive adds load; negative removes it.

Result

Fill in your panel and loads, then press “Check my panel”.

Estimate only — verify with a licensed electrician/engineer and your local code authority before final installation.