Appliance Wattage Electricity Running Cost Calculator (kWh)
Electricity billing is simple arithmetic that almost nobody performs: watts divided by a thousand gives kilowatts, multiplied by hours gives kilowatt-hours, multiplied by your tariff gives money. The surprise is usually scale — a 1,500 W space heater run four hours a day through winter costs more than a fridge running continuously all year.
Every 100 W running continuously costs about $245 a year at your tariff.
| Hours per day | kWh per day | Monthly cost | Annual cost |
|---|---|---|---|
| 1 | 1.50 | $12.78 | $153 |
| 2 | 3.00 | $25.57 | $307 |
| 4 | 6.00 | $51.14 | $613 |
| 6 | 9.00 | $76.71 | $920 |
| 8 | 12.00 | $102.28 | $1,226 |
| 12 | 18.00 | $153.42 | $1,840 |
| 24 | 36.00 | $306.84 | $3,679 |
Nameplate wattage versus real draw
The rating on the label is peak draw, not average. Thermostatically controlled appliances — fridges, air conditioners, heaters, ovens — cycle on and off, typically running thirty to sixty percent of the clock. For those, enter the hours the compressor or element actually runs, or use the annual kWh figure from the energy label instead.
Standby loads add up
A typical household carries fifteen to thirty devices drawing one to five watts each while idle. That vampire load commonly totals fifty to a hundred watts continuously, which is five to ten percent of an average electricity bill for electricity that does nothing at all.
Tariff structures change the answer
Flat-rate tariffs make this calculation exact. Time-of-use tariffs can triple the peak-period rate, so shifting the dishwasher, washing machine and EV charging to off-peak hours often saves more than replacing the appliance. Tiered tariffs raise the marginal rate once you cross a monthly threshold.
Typical appliance wattage and running cost
| Appliance | Wattage | Typical daily use | kWh / year | Annual cost at $0.28 |
|---|---|---|---|---|
| LED bulb | 9 W | 5 h | 16 | $4.60 |
| Laptop | 60 W | 8 h | 175 | $49 |
| Desktop + monitor | 250 W | 8 h | 730 | $204 |
| Refrigerator | 150 W (cycling) | 8 h effective | 438 | $123 |
| Washing machine | 500 W | 1 h | 183 | $51 |
| Tumble dryer | 3,000 W | 0.7 h | 767 | $215 |
| Air conditioner (1.5 t) | 1,500 W | 6 h | 3,285 | $920 |
| Electric space heater | 2,000 W | 4 h | 2,920 | $818 |
| Electric oven | 2,400 W | 0.5 h | 438 | $123 |
People also ask
How do I calculate the running cost of an appliance?
Divide the wattage by 1,000 to get kilowatts, multiply by hours used, then multiply by your per-kWh tariff. A 1,500 W heater for four hours is 6 kWh, or $1.68 at 28 cents.
How much does standby power cost per year?
A device drawing 3 W continuously uses about 26 kWh a year — around $7. Across twenty devices that is well over $100 annually.
Which appliances use the most electricity?
Anything that heats or cools: tumble dryers, electric heaters, air conditioners, water heaters and ovens. Electronics are almost always trivial by comparison.
Three worked examples
Same engine, three different starting points — useful if you want to see how sensitive the answer is before you type your own numbers in.
Example 1: appliance wattage 1170 W, currency "USD $"
On the lower / more conservative end. Every 100 W running continuously costs about $245 a year at your tariff.
Example 2: appliance wattage 1500 W, currency "USD $"
A typical middle-of-the-road setup. Every 100 W running continuously costs about $245 a year at your tariff.
Example 3: appliance wattage 1950 W, currency "GBP £"
On the higher / more demanding end. Every 100 W running continuously costs about £245 a year at your tariff.
Quick answers about the Appliance Electricity Cost
What exactly does the Appliance Electricity Cost work out?
Electricity billing is simple arithmetic that almost nobody performs: watts divided by a thousand gives kilowatts, multiplied by hours gives kilowatt-hours, multiplied by your tariff gives money. You enter currency, appliance wattage, hours used per day and electricity tariff (plus 1 more optional details) and the result panel updates straight away, so you can compare two or three versions of the same question in a few seconds.
What do I need before I start?
Only 5 fields: currency, appliance wattage, hours used per day, electricity tariff and standby draw. Nothing else is needed and nothing is stored.
How is it calculated — nameplate wattage versus real draw?
The rating on the label is peak draw, not average. The same maths runs inside this page, so hand-checking the result on paper gives you the identical figure.
Why do two calculators give me different answers for appliance Electricity Cost?
A typical household carries fifteen to thirty devices drawing one to five watts each while idle. Different sites pick different assumptions, so always check which method a calculator states before you trust the gap between two numbers.
What does the "Typical appliance wattage and running cost" table on this page tell me?
It is the reference range this tool works against — 9 rows from "LED bulb" (9 W) up to "Electric oven" (2,400 W). Use it to sanity-check whether the number you just calculated sits where you expected it to.
Which currency should I pick?
The dropdown offers 4 choices — USD $, GBP £, EUR € and AUD A$. Pick the one that matches your real situation rather than the one you would like to be true; currency usually moves the final figure more than any other single input, so it is worth running it twice with the option above and below your guess.
Does it work in both metric and imperial (or another currency)?
Yes. The "Currency" control converts every field and every result, so you never have to convert anything by hand before typing it in. Switch it after entering your numbers and the output re-renders instantly in the new system.
Do I have to press a button or reload the page to see the result?
No. Appliance Electricity Cost runs completely inside your browser, so the moment you change a value the cards recalculate — there is no submit step, no page reload and no waiting for a server round trip. That also means it keeps working on a weak or intermittent mobile connection.
Is it free, and do you keep what I type?
It is free with no sign-up, no app install and no usage limit. Nothing you enter into Appliance Electricity Cost leaves your device — the calculation is JavaScript running locally, so there is no upload of your figures to DrHint or anyone else.
Can I use it on a phone?
Yes — the layout stacks to a single column on small screens and the number fields open the numeric keypad on both Android and iOS. Many people bookmark this page or add it to their home screen and re-open it whenever the question comes up.
Anything to be careful about with the result?
Divide the wattage by 1,000 to get kilowatts, multiply by hours used, then multiply by your per-kWh tariff. Treat the output as a well-grounded estimate for planning, not as a professional, legal or medical decision on its own.
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