ENERGY
Energy & power calculators
Understand electricity, appliances, cooling, backup power, solar and EV charging with transparent formulas you can adjust.
Energy
Electricity bill
Estimate a monthly electricity bill from power consumption and tariff.
Open calculator EnergyAppliance annual cost
Understand the running cost of any electrical appliance.
Open calculator EnergyLED replacement savings
Compare older bulbs with efficient LED lighting.
Open calculator EnergySolar payback
Estimate simple payback for a rooftop solar investment.
Open calculator EnergyAir conditioner cost
Estimate seasonal cooling costs.
Open calculator EnergyGenerator fuel expense
Budget the fuel needed for backup power.
Open calculator EnergyEV charging costs
Estimate the electricity cost of charging an electric car.
Open calculator EnergyStandby power cost
Discover the annual cost of always-on electronics.
Open calculatorGUIDES
Understand the assumptions
Energy guide
How to estimate electricity costs without fooling yourself
A practical framework for turning watts, hours and tariffs into a realistic electricity-cost estimate.
Read guide →Energy guideSolar payback explained: what the simple number misses
Learn how simple payback works and why financing, maintenance and battery replacement can change the decision.
Read guide →