Calculateur kWh vers watts
Convertit l’énergie (kWh) et la durée (heures) en puissance moyenne (watts). Utilise W = kWh × 1000 ÷ h. Tout dans votre navigateur.
How much energy was used or stored.
Over how long that energy was delivered/consumed.
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Table of Contents
Que signifie kWh → watts
Kilowatt-hours and watts measure two different things, which is why converting between them confuses a lot of people.
Watts (W) measure power — the rate at which energy is being used or produced at any given moment. A 2,000 W kettle consumes energy at twice the rate of a 1,000 W microwave.
Kilowatt-hours (kWh) measure energy — the total amount consumed or produced over a period of time. Your electricity bill is in kWh because your retailer cares about how much total energy you used, not how fast you were using it at any instant.
The relationship between them is time: energy = power × time. To go from kWh back to watts, you need to know the time window involved. The result is average power over your chosen duration. If your load fluctuates — an air conditioner cycling on and off, a phone charging from flat to full — the instantaneous draw varies, but the kWh-to-watts conversion gives you a useful planning average. For electricity bills, generator sizing, and battery runtime calculations, this average is usually exactly what you need.
Formula
Average power
W = kWh × 1000 ÷ h
Because 1 kWh = 1,000 Wh, and power is energy divided by time: W = (kWh × 1,000 Wh) ÷ h.
Related forms
kWh = (W × h) ÷ 1,000 — find energy from power and time
kW = kWh ÷ h — result in kilowatts instead of watts
Quick Reference
| Energy (kWh) | Hours (h) | Average Power (W) | Example |
|---|---|---|---|
| 0.5 kWh | 1 h | 500 W | Refrigerator running for an hour |
| 1 kWh | 1 h | 1,000 W | 1,000 W load for 1 hour |
| 1 kWh | 0.5 h | 2,000 W | 2,000 W load for 30 minutes |
| 2 kWh | 1 h | 2,000 W | Air conditioner for 1 hour |
| 3 kWh | 2 h | 1,500 W | Average 1,500 W over 2 hours |
| 10 kWh | 24 h | 417 W | Daily household average |
| 30 kWh | 24 h | 1,250 W | High-consumption day |
Real-World Examples
Electricity bill to average power
Your bill shows you used 450 kWh last month (30 days = 720 hours). Average power = 450 × 1,000 ÷ 720 = 625 W. That's the average rate your household consumed energy around the clock.
Solar panel daily output
Your 6.6 kW solar system produced 28 kWh yesterday across 8 hours of generation. Average output = 28 × 1,000 ÷ 8 = 3,500 W (3.5 kW average). The peak was higher; early morning and late afternoon were lower.
Battery runtime planning
You have a 10 kWh home battery and want to run a 2,000 W load. Rearranging: h = kWh × 1,000 ÷ W = 10 × 1,000 ÷ 2,000 = 5 hours of runtime.
EV charging
Your car charged from flat and consumed 60 kWh over 10 hours on a home charger. Average charge rate = 60 × 1,000 ÷ 10 = 6,000 W (6 kW) — consistent with a standard 7.2 kW home charger running at moderate efficiency.
FAQ
Pas toujours. kWh → watts donne une puissance moyenne sur ta durée. Les fiches techniques indiquent souvent une puissance instantanée ou en régime stable.
Convertis d’abord en heures : heures = minutes ÷ 60. Puis W = kWh × 1000 ÷ h.
Oui pour une estimation moyenne. Si la puissance varie, on obtient la moyenne à partir de l’énergie totale.
Parce que 1 kWh = 1000 Wh. Diviser Wh par les heures donne les watts.