Electrical & Electronics
Electricity Cost & kWh Calculator
Estimate energy use and electricity costs for multiple appliances, including operating schedules and standby power.
Your inputs
Enter your price per kWh and a three-letter currency code, such as NOK or EUR. Power accepts units such as 100 W or 2 kW.
Your results
- Energy · Daily
- —
- Cost · Daily
- —
| Value | kWh | Cost |
|---|---|---|
| Weekly | — | — |
| Monthly | — | — |
| Yearly | — | — |
kWh = W × h / 1000Daily results are weekly averages. A month is 30 days and a year is 365 days. Standby power applies whenever an appliance is not active. Fixed charges are excluded.
Estimate appliance electricity use and cost
Compare a repeating weekly appliance schedule at a single electricity tariff. The calculator combines active use and standby consumption, then projects the daily average into longer periods. It is useful for comparing appliances or schedules; the result is an energy estimate rather than a complete electricity bill.
Step by step
- Enter the price per kWh and a currency code such as EUR. Add a row for each appliance type, using its measured or estimated active power in W.
- Set hours per operating day, operating days per week and quantity. Enter standby power per appliance separately; the model applies it during every remaining hour of the week.
- Review daily, weekly, monthly and yearly energy and cost, plus the appliance breakdown. Change one assumption at a time to compare schedules, then print the calculation if needed.
Settings and limits
- Power and quantity
- The active and standby powers are per appliance; quantity multiplies both. W measures power, while kWh measures energy. For cycling appliances, use a representative average power during the operating hours rather than assuming the nameplate power is continuous.
- Time periods
- Operating hours must be between 0 and 24 per day and operating days between 0 and 7 per week. Weekly active hours equal hours × days. Standby uses the remainder of the 168-hour week. Monthly and yearly projections use 30 and 365 days.
- Tariff and currency
- Cost equals energy × tariff. The currency code changes formatting; it does not convert prices. The calculation uses a constant tariff and excludes standing charges, separate taxes, tiered prices and time-of-use rates.
Worked example
Enter one appliance at 60 W, 4 hours per day, 7 days per week and 2 W standby, with an illustrative tariff of 0.25 EUR/kWh. The table lists each projection by its number of days, d.
| d | kWh | EUR |
|---|---|---|
| 1 | 0.28 | 0.07 |
| 7 | 1.96 | 0.49 |
| 30 | 8.4 | 2.10 |
| 365 | 102.2 | 25.55 |
Active use is 1.68 kWh per week and standby adds 0.28 kWh, giving 1.96 kWh weekly or 0.28 kWh daily. The estimated daily cost is 0.07 EUR; the 30-day projection is 8.4 kWh and 2.10 EUR.
Questions and troubleshooting
Why is standby included on non-operating days?
The model assumes the appliance stays connected and consumes the entered standby power whenever it is not active. If it is fully disconnected outside the schedule, set standby power to zero. For mixed behavior, use an average standby estimate.
Why does the monthly result differ from my bill?
The projection repeats the weekly schedule, uses a fixed month length and includes only the entered energy tariff. Actual calendar dates, changing usage and billing charges can differ. Compare energy readings over the same period before adjusting the estimate.
Why are the results blank?
Check the tariff, currency code and every appliance row. Power cannot be negative, quantity must be a positive whole number, and hours or days cannot exceed their allowed ranges. Correct the highlighted input or reset the calculator.