Calculadora de watts para kWh
Converte potência (watts) e duração (horas) em energia (kWh). Usa kWh = W × h ÷ 1,000. Tudo no navegador.
How much power the load uses on average.
How long that power is applied.
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Table of Contents
O que significa watts para kWh
Watts (W) measure power — the rate at which energy is being used or produced. Kilowatt-hours (kWh) measure energy — the total amount used over a period of time.
To convert between them, you need duration: energy = power × time.
The result is the total energy consumed or produced across your chosen time window (not an instantaneous reading).
If your load fluctuates — like a refrigerator cycling or an EV charger session starting/stopping — watts-to-kWh still gives a useful total based on your average power over the window.
Formula
Energy in kWh
kWh = W × h ÷ 1,000
Because 1 kWh = 1,000 Wh, and energy is power multiplied by time in hours: kWh = (W × h) ÷ 1,000.
Related forms
Wh = W × h — find watt-hours
MWh = kWh ÷ 1,000 — result in megawatt-hours
Quick Reference
| Power (W) | Hours (h) | Energy (kWh) | Example use |
|---|---|---|---|
| 500 W | 1 h | 0.5 kWh | 500W for 1 hour |
| 1,000 W | 1 h | 1 kWh | 1,000W for 1 hour |
| 2,000 W | 0.5 h | 1 kWh | 2,000W for 30 minutes |
| 2,000 W | 1 h | 2 kWh | 2,000W for 1 hour |
| 1,500 W | 2 h | 3 kWh | Average 1,500W over 2 hours |
| 417 W | 24 h | 10 kWh | Daily average (approx) |
| 1,250 W | 24 h | 30 kWh | High-consumption day |
Real-World Examples
Space heater runtime
A 1,500 W space heater running for 3 hours uses 1,500 × 3 ÷ 1,000 = 4.5 kWh.
EV charging session
A 7.2 kW home charger running for 5 hours consumes 7,200 × 5 ÷ 1,000 = 36 kWh.
Refrigerator day use
If your refrigerator averages 150 W over 24 hours, that is 150 × 24 ÷ 1,000 = 3.6 kWh per day.
Generator/inverter energy
A 2,000 W load running for 8 hours produces 2,000 × 8 ÷ 1,000 = 16 kWh of energy.
FAQ
Not exactly. Device labels typically describe instantaneous power (W) or energy usage patterns. Watts-to-kWh tells you the total energy over a specific duration, which is what electricity bills charge for (kWh).
Convert minutes to hours first: h = minutes ÷ 60. Then use kWh = W × h ÷ 1,000. The calculator handles it automatically if you enter decimal hours.
Yes for average planning. Solar and battery power varies throughout the day, but if you use an average watts value over the window, watts-to-kWh gives a practical energy total.
Because 1 kWh = 1,000 Wh. Multiplying watts by hours gives watt-hours; dividing by 1,000 converts Wh to kWh.
Bills charge per kWh consumed. If you know the average power (watts) of what you run and how long you run it, watts-to-kWh directly estimates the kWh you will use.
kW (kilowatts) is instantaneous power — how fast energy flows right now. kWh (kilowatt-hours) is energy — the accumulation of that power over time. For example: a 3 kW system running for 4 hours produces 12 kWh of energy.