Kilowatt-hours to Megajoules (kWh to MJ)

Formula

1 kWh = 3.6 MJ

megajoules = kilowatt-hours × 3.6 — reverse: kilowatt-hours = megajoules × 0.2777777778

The factor is derived from the SI definitions of both units (base unit: J) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.

Worked examples

• 5 kWh = 18 MJ
• 12.5 kWh = 45 MJ
• 100 kWh = 360 MJ

Kilowatt-hours to megajoules conversion table

FAQ

How many megajoules are in one kilowatt-hour?

1 kWh = 3.6 MJ. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

What is the formula to convert kilowatt-hours to megajoules?

Multiply the value in kilowatt-hours by 3.6: megajoules = kilowatt-hours × 3.6. For example, 5 kWh = 18 MJ.

How do I convert megajoules back to kilowatt-hours?

Multiply by the inverse factor 0.2777777778 (kilowatt-hours = megajoules × 0.2777777778), or use the megajoules-to-kilowatt-hours page.

Related conversions

• Megajoules to kilowatt-hours (reverse)
• Energy Converter — all energy units in one tool
• Kilocalories (food calories) to Kilojoules
• Kilojoules to Kilocalories (food calories)
• Joules to Calories (small, thermochemical)
• Calories (small, thermochemical) to Joules
• Kilowatt-hours to BTU
• BTU to Kilowatt-hours
• BTU to Joules
• Joules to BTU

Machine access

• API: GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=kWh&to_unit=MJ
• MCP: server https://tttkmbb.com/mcp, tool convert_units with {"value":5,"from_unit":"kWh","to_unit":"MJ"}
• Markdown: https://tttkmbb.com/conversion/kwh-to-mj.md · JSON: https://tttkmbb.com/conversion/kwh-to-mj.json (add ?value= for a result) · Units: /api/v1/units?quantity=energy
• OpenAPI operationId: convert_units. Freshness: static. Authentication: none.

Sources

• NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors (standard)
• BIPM – The International System of Units (SI Brochure, 9th edition) (standard)
• Wikipedia – Conversion of units (reference)