Every question about home energy comes down to three numbers: how many watts a thing draws, how many hours it runs, and what you pay per kilowatt-hour. This site works that arithmetic out for you, appliance by appliance and system by system, and shows the assumptions so you can change them.
Start here: the US average residential rate is 18.44ยข per kWh, up 6.2 % over the past year. A 1,500 W space heater run six hours a day costs $49.79 a month at that rate. Your own rate is on your bill and is the only number that really matters.
Home Electricity Cost Calculator
Change any box. The result updates as you type.
Planning estimate. The rate box is prefilled with a regional average; the figure on your own bill is the one that matters. Power is draw while running, not while switched on.
What appliances cost to run
Wattage, run time and duty cycle for the things that actually move a bill. A refrigerator is plugged in all day but its compressor runs a third of that, and getting that distinction right is the difference between a useful estimate and a wrong one.
- Every appliance, cost per hour, day and month
- Space heaters, air conditioning, water heating and EV charging are where most bills are won or lost.
Understand your bill
Electricity rates by state
The same appliance costs four times more in Hawaii than in Idaho. Nothing about the appliance changes; the rate does. Each state page carries a full appliance cost table computed at that state own rate.
Solar, sized honestly
How many panels a given load actually needs, after the losses most calculators quietly skip: heat, dust, wiring, inverter conversion and imperfect orientation.
- Panels needed, appliance by appliance
- Solar System Size Calculator and Solar Payback Calculator for the whole house
Philippines
Meralco rates have risen roughly 70 percent in five years, which changes the arithmetic on everything from aircon to rooftop solar. This section runs in pesos at current Philippine rates.
- Appliance running costs at Meralco rates
- Aircon cost by horsepower and hours
- What your bill should be at any consumption
- Solar system prices, 1kW to 15kW and panels needed per appliance
- Rates by utility: Meralco, VECO, Davao Light
Calculators
Eighty of them, covering the decisions that involve real money: system sizing, payback, battery capacity, inverter selection, circuit loads and backup runtime.
Guides
- Solar — sizing, inverters, output losses, payback
- Batteries — capacity, LiFePO4, compatibility, economics
- EV charging — installation, speed, circuits, solar charging
- Heating and cooling — heat pumps, mini-splits, water heating
- Backup power — generators, batteries, whole-home planning
How the numbers are kept current
Rates, wattages and assumptions live in one central dataset rather than being typed into individual pages. When the national average rate moves, every figure across the site moves with it. Each page states the rate it used and the date it applies to, so you can see how stale a number is before you rely on it.
Costs on this page use a national average residential rate of 18.44¢ per kWh (August 2026, EIA-derived state residential averages). Your own rate is printed on your electricity bill and is the number that actually matters. Every figure here is recalculated from one central rate setting, so these tables move when the national average moves.