How many watt-hours are in one kilowatt-hour?

One kilowatt-hour (kWh) equals exactly 1,000 watt-hours (Wh). "Kilo" means 1,000, so 1 kWh = 1,000 Wh by definition.

How do I convert kWh to Wh?

Multiply the kilowatt-hour value by 1,000. For example, 3.5 kWh × 1,000 = 3,500 Wh.

How do I convert Wh to kWh?

Divide the watt-hour value by 1,000. For example, 2,500 Wh ÷ 1,000 = 2.5 kWh.

Why do electricity bills use kWh instead of Wh?

Household electricity use runs into the thousands of watt-hours per day. Kilowatt-hours keep the numbers manageable — a typical home uses 20–30 kWh per day, or 20,000–30,000 Wh. Utility meters read in kWh for this reason.

Is this conversion exact?

Yes. The conversion factor is exactly 1,000 — no approximation is involved. 1 kWh = 1,000 Wh by the SI definition of unit prefixes.

How does this relate to solar panel output?

Solar panels are rated in watts (peak power). Multiply by hours of sunlight to get watt-hours, then divide by 1,000 for kWh. A 400 W panel in 5 peak sun hours produces 2,000 Wh = 2 kWh per day.

Kilowatt Hours to Watt Hours Converter

Convert kilowatt-hours (kWh) to watt-hours (Wh) instantly. 1 kWh = 1,000 Wh exactly.

Energy Converter

Kilowatt-hours (kWh)

Watt-hours (Wh)

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Formula: Wh = kWh × 1,000 • kWh = Wh ÷ 1,000

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Reference Tables

Kilowatt-hours (kWh)	Watt-hours (Wh)

Device / Scenario	kWh	Wh

1 kWh = 1,000 Wh • Wh = kWh × 1,000 • kWh = Wh ÷ 1,000

Summary

This tool converts energy between kilowatt-hours (kWh) and watt-hours (Wh). The relationship is exact: 1 kWh = 1,000 Wh, so Wh = kWh × 1,000 and kWh = Wh ÷ 1,000. Kilowatt-hours appear on electricity bills and solar panel output reports. Watt-hours are common for smaller devices — phone batteries, light bulbs, small appliances. Understanding both units helps you compare battery specs, estimate energy costs, and size solar or EV systems.

How it works

Choose a direction: kWh to Wh (default) or Wh to kWh.
Enter a value in the input field.
The result appears instantly.
Use the swap button to reverse the conversion direction.
Click the copy button to copy the result to your clipboard.

Use cases

Convert your electricity bill reading from kWh to Wh for per-device energy calculations.
Size a solar panel system by converting daily kWh output to Wh for granular comparisons.
Compare battery pack capacities listed in kWh against small devices rated in Wh.
Estimate EV charging energy in Wh from a battery rated in kWh.
Convert appliance energy consumption from kWh to Wh for hourly cost breakdowns.
Cross-check generator output specs between kWh and Wh ratings.

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu