How do I convert BTU to cal?

Use the formula shown above or enter a value to see BTU converted to cal instantly.

What is the formula for BTU to cal?

The converter calculates cal by applying the category-specific conversion factor for Energy.

When should I use BTU vs cal?

BTU and cal are both part of the Energy category; pick the unit that matches your measurement context (e.g., scale, region, or industry standard).

Energy Conversion Guide

Convert BTU to cal

Use the live converter below to translate between British Thermal Unit (BTU) and Calorie (cal). Scroll further for quick examples, formula tips, and related units.

Formula insight: Most unit conversions use a simple multiplication or division by a conversion factor. The calculator shows the exact formula used.

Convert

BTU → cal

British Thermal Unit

BTU

Calorie

252.1644

cal

Rounded result (4 decimals max)

Formula

1 BTU = 252.1644 cal

Conversion sourcesTap or click to view references

The International System of Units (SI) — NIST Special Publication 330
National Institute of Standards and Technology (NIST). The SI Brochure (SP 330) is the definitive English edition of the BIPM SI tables. NIST’s edition lists the official constants and conversion factors tying inch-pound units to SI, which SwapUnits applies for length, mass, temperature, pressure, volume, and related conversions. See /standards/nist-si-tenfold for the complete decimal multiple/submultiple table. View source · View SI table

Results update as you type. Swap the direction to convert back from cal to BTU.

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BTU to cal quick table

Multiply any row by the same factor to scale results. Use the converter above to enter exact values with your own units.

British Thermal Unit (BTU)	Calorie (cal)
0.25 BTU	63.0411 cal
0.5 BTU	126.0822 cal
1 BTU	252.1644 cal
2 BTU	504.3288 cal
5 BTU	1,260.822 cal
10 BTU	2,521.644 cal
25 BTU	6,304.11 cal
100 BTU	25,216.4401 cal

cal back to BTU

Keep the reciprocal handy when double-checking calculations or undoing a conversion.

Calorie (cal)	British Thermal Unit (BTU)
0.25 cal	0.001 BTU
0.5 cal	0.002 BTU
1 cal	0.004 BTU
2 cal	0.0079 BTU
5 cal	0.0198 BTU
10 cal	0.0397 BTU
25 cal	0.0991 BTU
100 cal	0.3966 BTU

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