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 |
|---|---|---|---|
| Home Battery Size Calculator | Batteries & Backup | How many kWh of battery backup you need for an outage, and how much power it must deliver... | Open → |
| Inverter Size Calculator | Batteries & Backup | What size inverter you need: continuous and surge watts for your appliances, plus battery... | Open → |
| EV vs Gas Calculator | Electricity Costs | Compare the yearly running cost of an electric car and a petrol car, and how long the EV t... | Open → |
| Solar Battery Payback Calculator | Solar | How long a home battery takes to pay for itself by storing solar and shifting cheap off-pe... | Open → |
| Tankless vs Tank Water Heater Calculator | Heating & Cooling | Compare running costs of gas and electric tank, tankless and heat pump water heaters, with... | Open → |
| Solar Payback Calculator | Solar | How many years until solar panels pay for themselves, with export credits, price rises and... | Open → |
| LED Savings Calculator | Electricity Costs | How much switching to LED bulbs saves a year in electricity and replacement bulbs, and how... | Open → |
| Home Electricity Carbon Footprint Calculator | Electricity Costs | The CO2 from your home electricity using your country, state or province grid factor, with... | Open → |
| Attic Insulation Cost Calculator | Heating & Cooling | How many inches of insulation you need to reach the recommended R-value, what it costs and... | Open → |