Calculadora de kWh para watts
Converte energia (kWh) e duração (horas) em potência média (watts). Usa W = kWh × 1000 ÷ h. Tudo no navegador.
How much energy was used or stored.
Over how long that energy was delivered/consumed.
All calculations run in your browser. No data is sent to a server.
Table of Contents
O que significa kWh para 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
Not necessarily. A device's watt rating is its steady-state or maximum instantaneous draw under normal operating conditions. kWh-to-watts gives you the average power over a time window. For a constant load like a heater, they'll be identical. For variable loads like a washing machine or EV charger, the device rating and the kWh-derived average will differ — the average accounts for periods of lower draw within the total run time.
Convert to hours first: h = minutes ÷ 60. For example, 45 minutes = 0.75 hours. Then apply W = kWh × 1,000 ÷ 0.75. The calculator handles this automatically if you enter decimal hours.
Yes, for average planning purposes. Solar output varies with cloud cover and sun angle throughout the day, so kWh ÷ hours gives you the average generation rate — useful for sizing inverters, comparing daily output, or calculating how long a battery would last at a given load.
Because kilo means 1,000. One kilowatt-hour = 1,000 watt-hours. Multiplying by 1,000 converts kWh to Wh, and dividing by hours then gives watts. If you want the result in kilowatts instead of watts, skip the ×1,000 step: kW = kWh ÷ h.
Your bill charges you per kWh consumed — the total energy, not the rate. To estimate your average power draw from a bill, divide total kWh by the billing period in hours. A typical Australian household uses 15–20 kWh per day, which works out to an average of roughly 625–830 W around the clock.
kW (kilowatts) is instantaneous power — how fast energy flows right now. kWh (kilowatt-hours) is energy — the accumulation of that power over time. A 3 kW solar system running for 4 hours produces 12 kWh of energy. The confusion is common because electricity retailers, appliance manufacturers, and solar installers use both units, often in the same conversation.