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

Formula

1 cal = 4.184 J

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

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 cal = 20.92 J
• 12.5 cal = 52.3 J
• 100 cal = 418.4 J

Calories (small, thermochemical) to joules conversion table

FAQ

How many joules are in one calorie?

1 cal = 4.184 J. 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 calories (small, thermochemical) to joules?

Multiply the value in calories (small, thermochemical) by 4.184: joules = calories (small, thermochemical) × 4.184. For example, 5 cal = 20.92 J.

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

Multiply by the inverse factor 0.2390057361 (calories (small, thermochemical) = joules × 0.2390057361), or use the joules-to-calories (small, thermochemical) page.

Related conversions

• Joules to calories (small, thermochemical) (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=cal&to_unit=J
• MCP: server https://tttkmbb.com/mcp, tool convert_units with {"value":5,"from_unit":"cal","to_unit":"J"}
• Markdown: https://tttkmbb.com/conversion/calories-to-joules.md · JSON: https://tttkmbb.com/conversion/calories-to-joules.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)