Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

EV Home-Charging Solar Offset Calculator

Calculate how many kilowatts of extra solar capacity you need to cover your EV's home charging. Useful when sizing a rooftop solar addition for a new or existing electric vehicle.

Annual miles driven (mi/yr)

Vehicle energy use (kWh/100mi)

Home charging losses (%)

Peak sun hours (daily average) (h/day)

Solar system losses (%)

Share of charging to offset with solar (%)

Extra solar capacity for EV

2.77 kW

Few panelsSmall dedicated arrayMid-size additionLarge array

2-4 kW (about 5-10 panels) covers a typical commuter. The 2.77 kW example fully offsets 12,000 mi/yr; dropping to 50% offset would halve this to under 1.4 kW.

This is the added solar array size (kW DC) to offset your chosen share of EV charging; a typical residential panel is about 0.4 kW, so divide by ~0.4 to estimate panel count.

Solar Energy

Solar Load Calculator

Calculate the total daily energy demand of your home's lighting, appliances, and HVAC to correctly size a solar system. Use this before getting solar quotes to know exactly how many kilowatt-hours per day you need to generate.

Lighting Load (watts)

Appliances Load (watts)

HVAC Load (watts)

Average Daily Usage (hours)

System Efficiency Factor

Fill in the required fields to see your result.

Key differences

	EV Home-Charging Solar Offset Calculator	Solar Load Calculator
Category	Solar Energy	Solar Energy
Inputs required	6	5
Result	Extra solar capacity for EV (kW)	Required Solar Capacity (kW)
What it does	Calculate how many kilowatts of extra solar capacity you need to cover your EV's home charging. Useful when sizing a rooftop solar addition for a new or existing electric vehicle.	Calculate the total daily energy demand of your home's lighting, appliances, and HVAC to correctly size a solar system. Use this before getting solar quotes to know exactly how many kilowatt-hours per day you need to generate.