Kilojoules to BTU (kJ to BTU)

Formula

1 kJ = 0.947817 BTU

BTU = kilojoules × 0.9478171203 — reverse: kilojoules = BTU × 1.055055853

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 kJ = 4.73909 BTU
• 12.5 kJ = 11.8477 BTU
• 100 kJ = 94.7817 BTU

Kilojoules to BTU conversion table

FAQ

How many BTU are in one kilojoule?

1 kJ = 0.947817 BTU. 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 kilojoules to BTU?

Multiply the value in kilojoules by 0.9478171203: BTU = kilojoules × 0.9478171203. For example, 5 kJ = 4.73909 BTU.

How do I convert BTU back to kilojoules?

Multiply by the inverse factor 1.055055853 (kilojoules = BTU × 1.055055853), or use the BTU-to-kilojoules page.

Related conversions

• BTU to kilojoules (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=kJ&to_unit=BTU
• MCP: server https://tttkmbb.com/mcp, tool convert_units with {"value":5,"from_unit":"kJ","to_unit":"BTU"}
• Markdown: https://tttkmbb.com/conversion/kj-to-btu.md · JSON: https://tttkmbb.com/conversion/kj-to-btu.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)