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Convert Kilojoules to Kilowatt Hours

Instantly convert Kilojoules (kJ) to Kilowatt Hours (kWh) with our free online calculator.

Reviewed by Christopher FloiedUpdated

Formula: kJ to kWhmultiply by 2.7778e-4

Reference Table

Kilojoules (kJ)Kilowatt Hours (kWh)
10.000277778
50.00138889
100.00277778
250.00694444
500.0138889
1000.0277778

How to Convert Kilojoules to Kilowatt Hours

Formula

To convert Kilojoules (kJ) to Kilowatt Hours (kWh): multiply by 2.7778e-4

Step-by-Step

  1. Start with your value in Kilojoules (kJ).
  2. Multiply by 2.7778e-4 to perform the conversion.
  3. The result is your value expressed in Kilowatt Hours (kWh).

Conversion Factor

1 kJ = 0.000277778 kWh

Reverse Factor

1 kWh = 3600 kJ

Worked Example

Convert 25 Kilojoules to Kilowatt Hours: 25 kJ = 0.00694444 kWh

About Kilojoule (kJ)

A metric unit of energy equal to exactly 1,000 joules. Kilojoules are the working unit for food-energy labelling outside the United States — Australia and New Zealand display kJ-only nutrition panels per FSANZ standards 1.2.7 / 1.2.8, the European Union requires kJ alongside kcal per EU Regulation 1169/2011, and Codex Alimentarius (the international food labelling standard) uses kJ. Reference values: a Big Mac is ~2,220 kJ, an adult daily energy intake is 8,000-10,500 kJ (about 2,000-2,500 kcal) per WHO/FAO Recommended Dietary Allowances, a 350 mL soft drink ~600 kJ. The kJ is also the natural engineering unit for small-scale mechanical work (joules per stroke on a punch press), small-cell battery capacity (e.g., a smartphone Li-ion at ~40 kJ), and small-scale thermodynamic calculations like an espresso machine's per-shot energy budget (~20 kJ). 1 kJ = 0.2389 kcal = 0.948 BTU = 277.8 mWh.

About Kilowatt Hour (kWh)

The global standard unit of electrical energy billing — exactly one kilowatt of power consumed (or generated) for exactly one hour, equal to 3,600,000 joules (3.6 MJ). The kWh is the universal residential and commercial electricity meter unit per IEC 62052 / ANSI C12.20 metering standards. Reference values: a typical US household consumes ~900 kWh per month (~30 kWh/day), the US national average residential electricity rate is ~$0.16/kWh as of 2025 EIA data, EV battery capacities are quoted in kWh (Tesla Model 3 Long Range 75 kWh, Model S Plaid 95 kWh, Ford F-150 Lightning Extended Range 131 kWh), residential solar systems are sized by expected annual kWh production (a 6 kW rooftop array typically produces 7,000-10,000 kWh/year depending on insolation), EV efficiency runs 0.25-0.35 kWh per mile (3-4 mi/kWh). The wholesale electricity market trades in MWh (megawatt-hours) and the bulk-power grid is balanced in GWh and TWh. 1 kWh = 3.6 MJ = 3,412 BTU = 860 kcal.

Quick Facts

  • 1 Kilojoule equals 0.000277778 Kilowatt Hours
  • 1 Kilowatt Hour equals 3600 Kilojoules
  • Kilojoule is a unit of energy
  • Kilowatt Hour is a unit of energy
  • This conversion is commonly used in nutrition, electrical billing, physics, and mechanical engineering
  • The Kilojoule belongs to the metric system

Common Kilojoule to Kilowatt Hour Conversions

Kilojoules (kJ)Kilowatt Hours (kWh)
0.010.00000277778
0.10.0000277778
0.250.0000694444
0.50.000138889
10.000277778
20.000555556
30.000833333
50.00138889
100.00277778
150.00416667
200.00555556
250.00694444
500.0138889
750.0208333
1000.0277778
2500.0694444
5000.138889
10000.277778
50001.38889
100002.77778

Understanding Kilojoules

The Kilojoule (symbol: kJ) is a unit of energy. A metric unit of energy equal to exactly 1,000 joules. Kilojoules are the working unit for food-energy labelling outside the United States — Australia and New Zealand display kJ-only nutrition panels per FSANZ standards 1.2.7 / 1.2.8, the European Union requires kJ alongside kcal per EU Regulation 1169/2011, and Codex Alimentarius (the international food labelling standard) uses kJ. Reference values: a Big Mac is ~2,220 kJ, an adult daily energy intake is 8,000-10,500 kJ (about 2,000-2,500 kcal) per WHO/FAO Recommended Dietary Allowances, a 350 mL soft drink ~600 kJ. The kJ is also the natural engineering unit for small-scale mechanical work (joules per stroke on a punch press), small-cell battery capacity (e.g., a smartphone Li-ion at ~40 kJ), and small-scale thermodynamic calculations like an espresso machine's per-shot energy budget (~20 kJ). 1 kJ = 0.2389 kcal = 0.948 BTU = 277.8 mWh.

It belongs to the metric measurement system.

Kilojoules are commonly used in nutrition, electrical billing, physics, and mechanical engineering.

Understanding Kilowatt Hours

The Kilowatt Hour (symbol: kWh) is a unit of energy. The global standard unit of electrical energy billing — exactly one kilowatt of power consumed (or generated) for exactly one hour, equal to 3,600,000 joules (3.6 MJ). The kWh is the universal residential and commercial electricity meter unit per IEC 62052 / ANSI C12.20 metering standards. Reference values: a typical US household consumes ~900 kWh per month (~30 kWh/day), the US national average residential electricity rate is ~$0.16/kWh as of 2025 EIA data, EV battery capacities are quoted in kWh (Tesla Model 3 Long Range 75 kWh, Model S Plaid 95 kWh, Ford F-150 Lightning Extended Range 131 kWh), residential solar systems are sized by expected annual kWh production (a 6 kW rooftop array typically produces 7,000-10,000 kWh/year depending on insolation), EV efficiency runs 0.25-0.35 kWh per mile (3-4 mi/kWh). The wholesale electricity market trades in MWh (megawatt-hours) and the bulk-power grid is balanced in GWh and TWh. 1 kWh = 3.6 MJ = 3,412 BTU = 860 kcal.

It belongs to the metric measurement system.

Kilowatt Hours are commonly used in nutrition, electrical billing, physics, and mechanical engineering.

Why Convert Kilojoules to Kilowatt Hours?

Converting energy between Kilojoules and Kilowatt Hours is common in physics, nutrition, and engineering. Electricity bills use kilowatt-hours, food labels list calories or kilojoules, and mechanical engineers work with joules and BTUs. Reliable conversion helps professionals and consumers compare energy values across different contexts.

Frequently Asked Questions

How do I convert Kilojoules to Kilowatt Hours?

A metric unit of energy equal to exactly 1,000 joules. To convert Kilojoules to Kilowatt Hours, multiply by 2.7778e-4. For example, 25 kJ equals 0.00694444 kWh.

How many Kilowatt Hours are in 1 Kilojoule?

There are 0.000277778 Kilowatt Hours in 1 Kilojoule.

How many Kilojoules are in 1 Kilowatt Hour?

There are 3600 Kilojoules in 1 Kilowatt Hour.

What is the formula for Kilojoule to Kilowatt Hour conversion?

The formula is: multiply by 2.7778e-4. This means 1 kJ = 0.000277778 kWh.

Is a Kilojoule bigger than a Kilowatt Hour?

Yes. One Kilojoule is larger than one Kilowatt Hour because 1 kJ equals 0.000277778 kWh, which is less than 1.

When do you need to convert between Kilojoules and Kilowatt Hours?

The global standard unit of electrical energy billing — exactly one kilowatt of power consumed (or generated) for exactly one hour, equal to 3,600,000 joules (3. Kilojoule and Kilowatt Hour are both energy units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

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