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Energy Converter

Turn a stored quantity of energy into another unit. The SI unit is the joule. This is not a power converter and it does not turn watt-hours into milliamp-hours.

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How to convert kilowatt-hours

  1. Enter the energy figure. The form starts at 1 kilowatt-hour.
  2. Keep From as Kilowatt-hours and To as Joules, or pick kilojoules, calories, watt-hours, or BTU (IT).
  3. Read the joule row, then scan the table for every energy unit on this page.
  4. Press Swap units to reverse the pair. Meter readings stay on this device.

Kilowatt-hour

SI energy (joule)

SI unitJoule (J), one newton-meter
Kilowatt-hour1 kWh = 3,600,000 J
Watt-hour1 Wh = 3600 J
Thermochemical calorie1 cal = 4.184 J
Kilocalorie1 kcal = 4184 J (food Calorie)
IT BTU1 BTU (IT) = 1055.05585262 J

What this energy converter does

Energy is a quantity you can store. Power is a rate. This page multiplies your value by a fixed factor into joules, then into kilojoules, thermochemical calories, kilocalories, watt-hours, kilowatt-hours, or International Table BTU. One kilowatt-hour is exactly 3.6 million joules because 1 W = 1 J/s and one hour is 3600 s.

Rates such as watts, kilowatts, and mechanical horsepower belong on the power converter and horsepower to kilowatts. Current from watts and volts lives on watts to amps.

Factors this page uses

The engine keeps joules as the canonical unit. 1 kWh = 3.6e6 J. 1 Wh = 3600 J. 1 kcal = 1000 thermochemical calories = 4184 J. The calorie here is the thermochemical calorie (4.184 J), not the nutrition Calorie printed on food labels. That large Calorie is one kilocalorie. The BTU on this list is the International Table BTU, 1055.05585262 J, not a mean or thermochemical BTU variant.

Nearby energy jobs

Utility bills quote kilowatt-hours. Physics labs quote joules and kilojoules. HVAC sheets often quote BTU. Food energy is kilocalories. The unit converter can switch dimension if you landed on energy by mistake. This page never asks for voltage, so it cannot turn watt-hours into milliamp-hours. Battery mAh needs V because Wh = (mAh / 1000) × V.

When to convert energy here

Use this form to check a bill line in joules, to compare a BTU rating with a kWh figure, or to move a lab value from calories into watt-hours. Leave appliance current, horsepower, and wiring checks on the power and watts-amps pages.

What this page does not do

This is energy, not power. It does not add a cost per kWh, a tariff, or a live grid price. It does not convert milliamp-hours. Nothing you type is uploaded. IEEE floating point in this browser rounds the last digits of long BTU products.

Energy converter questions

Is a kilowatt-hour a unit of power?
No. A kilowatt is power. A kilowatt-hour is energy: one kilowatt running for one hour, equal to 3,600,000 J.
What calorie does this converter use?
The thermochemical calorie, 4.184 J. A food Calorie (capital C) is 1 kcal = 4184 J.
Which BTU is on the list?
The International Table BTU, 1055.05585262 J. Other historical BTU definitions are not listed.
Can I convert watt-hours to milliamp-hours?
No. That job needs a voltage. This page only converts energy units.
How do I reach watts or horsepower?
Open the power converter or horsepower to kilowatts. Those pages convert rates, not stored energy.
Does CZNull receive my meter reading?
No. The factors run in this tab.