Home energy calculators
Free calculators for solar, batteries and backup, heating and cooling, and electricity costs. Each one shows the formula, the assumptions and a worked example.
All calculators
18 calculators| Calculator | Topic | Answers | Open |
|---|---|---|---|
| Solar Panel Calculator | Solar | How many solar panels you need, what size system and how much roof space, from your electr... | Open → |
| Electricity Cost Calculator | Electricity Costs | What any appliance costs to run per hour, day, month and year at your electricity price. | Open → |
| Generator Size Calculator | Batteries & Backup | What size generator you need: running and starting watts for the appliances you want to ke... | Open → |
| Space Heater Cost Calculator | Heating & Cooling | What a space heater costs to run per hour, day and month at your electricity price. | Open → |
| EV Charging Cost Calculator | Electricity Costs | What it costs to charge an electric car at home and at public chargers, per month, per mil... | Open → |
| kWh Cost Calculator | Electricity Costs | Turn kWh into money: your bill with fixed charges and tax, and the real price you pay per... | Open → |
| AC Running Cost Calculator | Heating & Cooling | What a window, portable, mini-split or central air conditioner costs to run per hour, mont... | Open → |
| Battery Runtime Calculator | Batteries & Backup | How long a portable power station or home battery will run your appliances, with or withou... | Open → |
| Solar Panel Output Calculator | Solar | How many kWh a solar panel or system produces per day, month and year where you live. | Open → |