Joules to Kilowatt-hours (J to kWh)

Formula

1 J = 2.77778e-7 kWh

kilowatt-hours = joules × 2.777777778e-7 — reverse: joules = kilowatt-hours × 3600000

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 J = 0.00000138889 kWh
• 12.5 J = 0.00000347222 kWh
• 100 J = 0.0000277778 kWh

Joules to kilowatt-hours conversion table

FAQ

How many kilowatt-hours are in one joule?

1 J = 2.77778e-7 kWh. 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 joules to kilowatt-hours?

Multiply the value in joules by 2.777777778e-7: kilowatt-hours = joules × 2.777777778e-7. For example, 5 J = 0.00000138889 kWh.

How do I convert kilowatt-hours back to joules?

Multiply by the inverse factor 3600000 (joules = kilowatt-hours × 3600000), or use the kilowatt-hours-to-joules page.

Related conversions

• Kilowatt-hours to joules (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 Megajoules
• Megajoules to Kilowatt-hours
• Kilowatt-hours to BTU
• BTU to Kilowatt-hours

Machine access

• API: GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=J&to_unit=kWh
• MCP: server https://tttkmbb.com/mcp, tool convert_units with {"value":5,"from_unit":"J","to_unit":"kWh"}
• Markdown: https://tttkmbb.com/conversion/joules-to-kwh.md · JSON: https://tttkmbb.com/conversion/joules-to-kwh.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)