Complete Electricity Cost Calculator Guide
A complete guide to estimating electricity cost from watts, kWh, hours, rates, and monthly usage.
Last updated: May 2026
Who this guide is for
This guide is the main electricity cost hub for estimating appliances, heaters, AC units, PCs, pool pumps, EV charging, and home office usage.
What to compare
Check watts, hours, days used, duty cycle, and all-in kWh rate. For cycling appliances, estimate active runtime rather than plugged-in time.
Buying guidance
Compare operating cost before buying energy-heavy products. A cheaper device can cost more over time if it runs many hours at high wattage.
Use the calculator first
Start with the related calculator, then use this guide to interpret the result. Sizes, costs, capacities, and product ratings should always be checked against current labels, reviews, and your actual room or aquarium setup.