Understand the estimate

Electricity formulas, units, and real-world limits

Three focused guides explain the core equation, the difference between watts and kWh, and why a simple estimate may differ from a bill or meter.

Electricity formula5 min read

How to calculate electricity cost from watts and time

Convert watts and runtime to kWh, then multiply by your price per kWh to estimate appliance running cost.

Power and energy5 min read

Learn why watts measure power, kWh measure energy, and runtime is required to convert between them.

Estimate boundaries5 min read

Nameplate power, duty cycles, standby use, tariff tiers, taxes, and fixed charges can separate a simple estimate from a real bill.