Select a category and enter your values below
Multiple conversions
To convert from Kilowatt-hour (kWh) to Watt-second (Ws), use the following formula:
Watt-second (Ws)
= 60 × 60 × 1000× Kilowatt-hour (kWh)
= 3600000× Kilowatt-hour (kWh)
To convert from Kilowatt-hour (kWh) to Watt-minute (Wm), use the following formula:
Watt-minute (Wm)
= 60 × 60 × 1000 × 160× Kilowatt-hour (kWh)
= 60000× Kilowatt-hour (kWh)
To convert from Kilowatt-hour (kWh) to Watt-hour (Wh), use the following formula:
Watt-hour (Wh)
= 60 × 60 × 1000 × 160 × 60× Kilowatt-hour (kWh)
= 1000× Kilowatt-hour (kWh)
To convert from Kilowatt-hour (kWh) to Milliwatt-hour (mWh), use the following formula:
Milliwatt-hour (mWh)
= 60 × 60 × 1000 × 13.6× Kilowatt-hour (kWh)
= 106× Kilowatt-hour (kWh)
To convert from Kilowatt-hour (kWh) to Megawatt-hour (MWh), use the following formula:
Megawatt-hour (MWh)
= 60 × 60 × 1000 × 160 × 60 × 106× Kilowatt-hour (kWh)
= 0.001× Kilowatt-hour (kWh)
To convert from Kilowatt-hour (kWh) to Gigawatt-hour (GWh), use the following formula:
Gigawatt-hour (GWh)
= 60 × 60 × 1000 × 160 × 60 × 109× Kilowatt-hour (kWh)
= 10-6× Kilowatt-hour (kWh)
To convert energy from kilowatt hours (kWh) to joules (J), multiply by 3,600,000 (3.6 × 10⁶).
The factor is not arbitrary — it is built from the definition of the watt. One watt is one joule per second, so a kilowatt is 1,000 J/s. Sustain that for an hour, which is 3,600 seconds, and the energy delivered is 1,000 × 3,600 = 3,600,000 J. In compact form:
An electric car carries a 75 kWh battery, and a physics calculation needs that capacity in base SI units:
That is 270 MJ. For scale, it is roughly the chemical energy in 8 liters of gasoline — a comparison that only becomes possible once both quantities are expressed in joules.
| kWh | J |
|---|---|
| 0.001 | 3,600 |
| 1 | 3,600,000 |
| 10 | 36,000,000 |
| 75 | 270,000,000 |
| 100 | 360,000,000 |
| 1,000 | 3,600,000,000 |
The kilowatt hour and the joule measure exactly the same thing, and both are needed because they serve different conversations. The kWh is the unit of energy commerce: electricity meters count in it, utility tariffs are priced in it, battery capacities and appliance ratings are labeled in it, and national statistics aggregate it into GWh and TWh. The joule is the unit of energy physics: every equation in thermodynamics, mechanics and electromagnetism produces and consumes joules, because the joule alone cancels correctly against newtons, meters, watts and seconds.
The conversion is therefore the bridge between an electricity bill and a calculation. Sizing a solar array against a household's 900 kWh monthly consumption, checking whether a battery can supply a motor's mechanical work, comparing an electric vehicle's storage to a fuel tank's calorific value, or computing the temperature rise from an immersion heater's energy input — each begins by multiplying by 3.6 million. That the number is so large explains why the kWh exists at all: a typical home uses about 3.24 billion joules a month, a figure no meter would sensibly display.
Two clarifications save real confusion. First, kW and kWh are not interchangeable — a kilowatt is a rate, a kilowatt hour is an amount, and a 2 kW heater running for 30 minutes consumes 1 kWh, or 3.6 MJ. Second, watch the neighboring capitalizations and prefixes: kWh, kW·h and kWhr all mean the same thing, but kWh and MWh differ by a thousand, and mixing them into this multiplication produces an answer off by three orders of magnitude — always worth a glance at the anchor, since anything domestic should land in the millions or low billions of joules.
To convert from Kilowatt-hour (kWh) to Kilojoule (kJ), use the following formula:
Kilojoule (kJ)
= 60 × 60 × 1000 × 11000× Kilowatt-hour (kWh)
= 3600× Kilowatt-hour (kWh)
To convert from Kilowatt-hour (kWh) to Megajoule (MJ), use the following formula:
Megajoule (MJ)
= 60 × 60 × 1000 × 1106× Kilowatt-hour (kWh)
= 3.6× Kilowatt-hour (kWh)
To convert energy from kilowatt-hours (kWh) to gigajoules (GJ), multiply by 0.0036.
The factor is exact and comes straight from the definitions: one watt is one joule per second, so a kilowatt sustained for an hour delivers 1,000 J/s × 3,600 s = 3,600,000 J = 3.6 MJ. Expressed in gigajoules (10⁹ J), that is 0.0036 GJ per kWh.
The reverse anchor is the one most people end up memorizing:
A factory's monthly electricity consumption is 48,500 kWh, and a corporate energy report requires gigajoules:
Reverse direction: a district-heating bill of 25 GJ equals 25 × 277.78 ≈ 6,944 kWh.
| kWh | GJ |
|---|---|
| 100 | 0.36 |
| 277.78 | 1 |
| 1,000 | 3.6 |
| 5,000 | 18 |
| 10,000 | 36 |
| 100,000 | 360 |
| 277,778 | 1,000 |
The kWh and the GJ are the billing units of two different industries that constantly need to talk to each other. Electricity is metered and sold in kWh everywhere. Natural gas and district heating are billed in GJ in Canada and Australia, and energy statistics, carbon-accounting protocols and engineering feasibility studies almost always tabulate totals in GJ or TJ because joules are the SI unit.
The conversion therefore appears whenever fuels are compared on equal footing: deciding between a gas boiler (GJ) and a heat pump (kWh), computing the site-wide energy intensity of a building, or filling in a greenhouse-gas inventory where every energy stream must be converted to a common unit before applying emission factors. A practical benchmark helps keep results plausible: a typical Canadian home burns 80–120 GJ of natural gas a year — the equivalent of 22,000–33,000 kWh — while its electricity use is usually well under half of that.
To convert from Kilowatt-hour (kWh) to calorie (cal), use the following formula:
calorie (cal)
= 60 × 60 × 1000 × 14.184× Kilowatt-hour (kWh)
= 860420.65009560229446× Kilowatt-hour (kWh)
With 14.184 is the ratio between the base units calorie (cal) and Joule (J).
To convert from Kilowatt-hour (kWh) to Kilocalorie (kcal), use the following formula:
Kilocalorie (kcal)
= 60 × 60 × 1000 × 14.184 × 11000× Kilowatt-hour (kWh)
= 860.42065009560229446× Kilowatt-hour (kWh)
With 14.184 is the ratio between the base units calorie (cal) and Joule (J).
A kilowatt-hour (kWh) is a measurement of energy. It's the standard unit your utility company uses to measure how much electricity you use.
While it has a technical definition (one kWh equals 3.6 million Joules), it's much easier to understand in terms of how you use appliances at home.
Your utility company uses the kilowatt-hour (kWh) to bill you for the total amount of electrical energy your home or business consumes over a period.
Every appliance, from your refrigerator to your television, has a power rating in watts.
When you use a 1,000-watt (or 1-kilowatt) appliance for one full hour, you consume exactly one kilowatt-hour of energy. This usage is tracked by your electric meter and shows up on your monthly bill.
A common point of confusion is the distinction between a kilowatt (kW) and a kilowatt-hour (kWh).
Here's a simple analogy to make it clear: Kilowatts (kW) are like your car's speed, and kilowatt-hours (kWh) are like the distance you travel.
Power (kW) measures how fast you're using energy right now (your speed).
Energy (kWh) measures the total amount of electricity you used over your entire journey (the distance you traveled).
To put it in perspective, one kilowatt-hour (kWh) is a significant amount of energy that can power various common household activities.
For example, a single kWh can let you:
This unit provides a tangible way to understand and track your daily energy consumption.