Electricity Bill Calculator
Running cost of an appliance per day, month and year.
Your figures
Result
How to use this tool
- Enter your own figures over the defaults — Appliance power, Hours used per day, Cost per kWh.
- The answer updates as you type. There is no button, and nothing is sent anywhere.
- Change Appliance power on its own to see how much it moves the result — the worked example below shows exactly that.
The wattage on an appliance label is its maximum draw. Devices that cycle — fridges, air conditioners, heaters — average well below it, so treat this as an upper bound for those.
How it works
This takes 3 inputs — appliance power, hours used per day, cost per kwh — and returns monthly cost, daily usage and yearly cost. The whole calculation happens in this page as you type: there is no submit button, no request, and nothing stored.
Because it recalculates on every keystroke you can use it as a sensitivity test rather than a one-shot answer. Moving appliance power alone from 1,500 to 1,650 changes monthly cost from 27.00 to 29.70 — the worked example below sets that out in full.
A worked example
Worked through with the figures the page already has in it: appliance power of 1,500 watts and hours used per day of 4, and the rest as shown, giving monthly cost of 27.00. These numbers come from running the calculator’s own code, not from being typed in here, so they cannot drift away from what you see on screen.
Starting from:
- Appliance power: 1,500 watts
- Hours used per day: 4
- Cost per kWh: 0.15
| Result | Value |
|---|---|
| Monthly cost | 27.00 |
| Daily usage | 6.00 kWh |
| Yearly cost | 328.50 |
What happens when one input moves
Holding everything else steady and changing Appliance power from 1,500 watts to 1,650 watts — 10% — moves the answer like this:
| Figure | 1,500 watts | 1,650 watts |
|---|---|---|
| Monthly cost | 27.00 | 29.70 |
| Daily usage | 6.00 kWh | 6.60 kWh |
| Yearly cost | 328.50 | 361.35 |
That is usually the number worth arguing over: it is easier to move than the headline amount, and the difference compounds across the whole term.
Electricity Bill Calculator — frequently asked questions
Where do I find the wattage?
On the rating label, usually on the back or base, or in the manual. A plug-in energy monitor gives real consumption.
What is a kWh?
One kilowatt drawn for one hour. A 1000 W appliance running for one hour uses 1 kWh — the unit your bill is priced in.
Why is my bill higher than this suggests?
This covers one appliance. Standby loads, heating and cooling, and water heating usually dominate a household bill.
Is this calculator free?
Yes, with no account, no limits and no data collection. It runs entirely in your browser.
Should I rely on this for a financial or medical decision?
No. It is a planning estimate built on standard formulas and stated assumptions. For decisions that matter, speak to a qualified professional who can account for your full circumstances.
How accurate is the Electricity Bill figure?
The arithmetic is exact. With the defaults on this page — appliance power 1500 watts, hours used per day 4, cost per kwh 0.15 — it returns monthly cost of 27.00. What limits accuracy is the assumptions, not the maths: change appliance power to 1650 watts and the same formula gives 29.70. Treat it as a well-founded estimate, not a quotation.
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Nothing is sent anywhere. The figures you type stay in this page and are never transmitted or stored — how that works.
Disclaimer. The formula is exact; the answer is only as good as the figures and assumptions above. Not financial, tax, medical or legal advice. Full disclaimer.