kWh to MJ Converter
1 kWh = 1,000 J/s × 3,600 s = 3,600,000 J = 3.6 MJ exactly. Multiply kWh by 3.6 to get MJ. This is the reverse of the MJ-to-kWh conversion and is equally exact, every unit in the...
Formula
Source: International System of Units (SI), NIST SP 811 | Last reviewed: June 27, 2026
Examples
1 kWh
= 3.6 MJ
1 kWh = 3.6 MJ exactly
10 kWh
= 36 MJ
10 kWh = 36 MJ
100 kWh
= 360 MJ
100 kWh = 360 MJ
1000 kWh
= 3600 MJ
1,000 kWh (1 MWh) = 3,600 MJ = 3.6 GJ
10000 kWh
= 36000 MJ
10,000 kWh (10 MWh) = 36,000 MJ = 36 GJ
Quick Reference Table
| kWh | MJ | Context |
|---|---|---|
| 1 | 3.6 | 1 kWh |
| 10 | 36 | Daily household electricity in moderate climate |
| 30 | 108 | Daily US household average (~30 kWh) |
| 100 | 360 | ~Monthly electric vehicle charging (500 mi) |
| 1000 | 3600 | 1 MWh, medium commercial monthly |
| 10000 | 36000 | 10 MWh, small industrial monthly |
Where is this used?
Multiply kWh by 3.6 to get MJ.
This is the reverse of the MJ-to-kWh conversion and is equally exact, every unit in the chain is an SI definition: 1 J = 1 kg·m²/s², 1 W = 1 J/s, 1 h = 3,600 s, mega = 10⁶.
The conversion appears when electrical energy consumption (universally in kWh) must be expressed in SI energy units (MJ or GJ) for scientific, international regulatory, or process engineering contexts.
For example, a facility that consumes 500,000 kWh of electricity per month is consuming 1,800,000 MJ (1,800 GJ or 1.8 TJ) of electrical energy, a value that can be directly compared to the facility's natural gas consumption of, say, 800 GJ (222,000 kWh-equivalent) to compute the total energy consumption on a common basis.
The kWh-to-MJ conversion is essential in life cycle assessment (LCA) and carbon footprint analysis under ISO 14040/14044, where all energy flows (electricity in kWh, natural gas in MJ or BTU, diesel in liters × MJ/L, coal in kg × MJ/kg) must be aggregated into a single primary energy consumption figure in MJ or GJ.
The ecoinvent LCA database (the world's most widely used LCA database, maintained by ETH Zurich and used by SimaPro, GaBi, and openLCA software) reports all energy values in MJ.
A product carbon footprint that involves 10 kWh of Chinese grid electricity (converted to 36 MJ, then multiplied by the Chinese grid emission factor of ~0.6 kg CO₂/MJ) yields 21.6 kg CO₂, the calculation chain runs through MJ regardless of the original electricity billing unit.
In the EU's Energy Efficiency Directive (EED) and the Energy Performance of Buildings Directive (EPBD), primary energy factors convert final energy consumption (metered in kWh for electricity and natural gas) to primary energy in kWh or MJ, a building that consumes 100 kWh/m²·yr of final energy with a primary energy factor of 1.8 consumes 180 kWh/m²·yr of primary energy, which is 648 MJ/m²·yr.
The kWh-to-MJ conversion (×3.6) and the reverse (÷3.6) are the most frequently used energy conversions in European energy policy analysis.
The factor 3.6 is exact, one of the very few unit conversions in all of engineering that has zero uncertainty.
Where kWh-to-MJ conversions appear in real engineering work.
Converting electricity consumption (kWh) to SI energy units (MJ/GJ) for life cycle assessment, carbon footprint analysis, and energy intensity metrics.
Expressing building energy consumption in MJ for European energy performance certification and regulatory compliance.
Aggregating diverse energy flows (electricity in kWh, natural gas in therms or MJ, fuel oil in liters, coal in kg) into a unified MJ or GJ energy balance for industrial energy management (ISO 50001).
Translating battery energy storage capacity from kWh (EV and grid battery standard) to MJ for comparison with chemical fuel energy content in process engineering feasibility studies.
Real-World Usage Scenarios
EU Energy Performance of Buildings Directive (EPBD) compliance
An office building in Berlin has annual energy consumption of 350,000 kWh. Converting to MJ for the EPBD reporting: 350,000 × 3.6 = 1,260,000 MJ = 1,260 GJ. Per the German Energieausweis (Energy Certificate) requirements, the building's primary energy consumption is reported as GJ/m²·yr. For a 5,000 m² floor area: 1,260 GJ / 5,000 m² = 252 MJ/m²·yr. The primary energy factor for German grid electricity is 1.8 (per EnEV/GEG regulations), so the primary energy is 1,260 × 1.8 = 2,268 GJ = 454 MJ/m²·yr. The kWh-to-MJ conversion is the foundation of this compliance calculation, every kWh must be converted to MJ before the primary energy factor is applied. A 1% error in the conversion corresponds to a 1% error in the reported primary energy, which could place the building in a different energy efficiency class (A+ to H in the German scale), with regulatory consequences.
Industry Standards Referenced
Frequently Asked Questions
Is 3.6 exactly the right factor?
Yes. 1 watt = 1 joule per second by SI definition. 1 hour = 3,600 seconds by definition (60 s/min × 60 min/hr). 1 kilo = 1,000 by SI prefix definition. 1 mega = 1,000,000 by SI prefix definition. Therefore 1 kWh = 1,000 × 3,600 = 3,600,000 J = 3.6 MJ. Every step in this chain is an exact definition, no measurement uncertainty, no experimental constant. This is one of the rare perfectly exact conversions in engineering.
What does this converter do?
This converter performs the unit conversion at standard conditions using the exact conversion factor. The result is displayed with appropriate precision for engineering use.
How accurate is the conversion?
The conversion factor used is exact or to four significant figures depending on the units. For most engineering calculations, the precision is more than sufficient. For precision work, consult the relevant NIST or ISO standards referenced on this page.
Reviewed for accuracy
Verified against SI definitions · Last reviewed: June 27, 2026
All calculations are for reference only. Always verify with manufacturer data and a qualified engineer for critical applications. Learn about our editorial process.