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Power and Energy

BTUtocal

Convert International Table BTUs (BTU) to thermochemical calories (cal).

Factor1 BTU = 252.1644 cal

Converter

BTU

Accepts numbers or expressions, e.g. 150 + 14.7

Result
252.164cal

Rendered to 6 significant figures.

Formula

Formula
cal = BTU × 252.1644

Multiply any value in International Table BTUs by 252.1644 to obtain the value in thermochemical calories.

Worked example

Convert 1 BTU to cal.

  1. 01Start with 1 BTU.
  2. 02Multiply by the conversion factor: 1 × 252.1644 = 252.164 cal.
Result1 BTU = 252.164 cal

Conversion table

BTUcal
1252.16
2504.33
51260.8
102521.6
205043.3
5012608
10025216
20050433
5001.2608e+5
10002.5216e+5

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from BTU to cal?
1 BTU equals 252.1644 cal. To convert, multiply the value in International Table BTUs by 252.1644.
How do I convert 1 BTU to cal?
1 BTU = 252.164 cal. For any value, multiply by 252.1644.
How do I convert cal back to BTU?
Divide by the same factor — or equivalently, multiply by 0.003965667. So 1 cal = 0.00396567 BTU.
When would I need to convert International Table BTU to thermochemical calorie?
Energy conversions are needed when reconciling fuel/electrical billing, calculating thermal duties, and aligning calorimetry or HHV/LHV figures across data sources.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).

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