Electricity Cost Calculator
Work out what your appliances cost to run per day, month and year.
Find Out Where Your Electricity Bill Goes
Add your appliances — pick from typical ones like a fridge, TV, gaming PC, kettle or space heater, or enter your own — with their power in watts, the hours a day they run and how many you have. Enter your price per kilowatt-hour from your bill, and see the energy each one uses and what it costs per day, month and year.
It is the quickest way to answer questions like “is it cheaper to run a heater or the central heating?”, “what does leaving the PC on overnight cost?”, or “how much will an EV add to my bill?” — and to find the one appliance quietly costing the most.
Key features
- 24 typical appliances with realistic wattages, or your own.
- Daily, monthly and yearly cost and kWh.
- Per-appliance breakdown to find the big consumers.
- Any currency and any price per kWh.
- Quantities — ten LED bulbs, two monitors.
This tool runs entirely inside your browser using native Web APIs. Your files and text are never uploaded to a server, never logged and never shared with third parties.
How to use: Electricity Cost Calculator
- Enter your price per kWh
It is on your bill as the unit rate. - Add appliances
Choose a typical one or type your own name and wattage. - Set hours per day
For fridges and heaters, the hours they actually run, not the hours they are on. - Read the totals
Sort out which devices dominate the cost.
Technical specifications
| Processing location | Entirely in your browser — no server round trip |
|---|---|
| Data uploaded | None. Files and text never leave your device |
| Price | Free — no account, no trial, no usage cap |
| Category | Calculators |
| Works offline | Yes, once the page has loaded |
| Browser support | Chrome 90+, Edge 90+, Firefox 90+, Safari 15+ |
| Interface languages | English, 中文, हिन्दी, Español, العربية |
Frequently asked questions
How do I convert watts to kWh?
Multiply watts by hours of use and divide by 1,000. A 2,000 W heater running for 3 hours uses 2,000 × 3 ÷ 1,000 = 6 kWh. At $0.28 per kWh that costs $1.68.
Where do I find an appliance’s wattage?
On the rating label or power adapter, usually as W or as volts × amps. A plug-in energy meter gives the real figure, which for many devices is well below the label maximum.
Why is my fridge’s estimate high?
A fridge compressor cycles on and off, so it draws full power only part of the day — often 6–10 hours’ worth. Enter the running hours, not 24.
Does standby power matter?
A few watts around the clock adds up: 10 W on standby all year is 88 kWh. Add standby devices with 24 hours per day to see their share.
What is a typical price per kWh?
It varies widely: roughly $0.15–0.30 in the US, £0.25–0.30 in the UK and €0.25–0.40 across much of Europe. Use the rate on your own bill.