Joules to Calories (small, thermochemical) (J to cal)

Formula

1 J = 0.239006 cal

calories (small, thermochemical) = joules × 0.2390057361 — reverse: joules = calories (small, thermochemical) × 4.184

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 = 1.19503 cal
• 12.5 J = 2.98757 cal
• 100 J = 23.9006 cal

Joules to calories (small, thermochemical) conversion table

FAQ

How many calories (small, thermochemical) are in one joule?

1 J = 0.239006 cal. 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 calories (small, thermochemical)?

Multiply the value in joules by 0.2390057361: calories (small, thermochemical) = joules × 0.2390057361. For example, 5 J = 1.19503 cal.

How do I convert calories (small, thermochemical) back to joules?

Multiply by the inverse factor 4.184 (joules = calories (small, thermochemical) × 4.184), or use the calories (small, thermochemical)-to-joules page.

Related conversions

• Calories (small, thermochemical) to joules (reverse)
• Energy Converter — all energy units in one tool
• Kilocalories (food calories) to Kilojoules
• Kilojoules to Kilocalories (food calories)
• Kilowatt-hours to Megajoules
• Megajoules to Kilowatt-hours
• 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=J&to_unit=cal
• MCP: server https://tttkmbb.com/mcp, tool convert_units with {"value":5,"from_unit":"J","to_unit":"cal"}
• Markdown: https://tttkmbb.com/conversion/joules-to-calories.md · JSON: https://tttkmbb.com/conversion/joules-to-calories.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)