Calorie (IT) to BTU (th) Converter

Energy Converter

27 units available

Decimals:

From

To

0.003971

1 cal (IT) = 0.003971 BTU

Formula:

BTU = cal (IT) × 0.0039709774

With your value: 1 cal (IT) = 0.00397098 BTU

How big is that?

Everyday references on a logarithmic scale, all expressed in calorie (it) so you can sanity-check the result.

Heartbeat (1/4.2 your value)0.239 cal (IT)

Your value1.00 cal (IT)

AA battery charge (2.4e+3× your value)2.39e+3 cal (IT)

Slice of bread (6.7e+4× your value)6.69e+4 cal (IT)

Daily food intake (2.0e+6× your value)2.01e+6 cal (IT)

Litre of petrol (8.2e+6× your value)8.17e+6 cal (IT)

Other Calorie (IT) to BTU (th) conversions

2 cal (IT) to BTU 3 cal (IT) to BTU 4 cal (IT) to BTU 5 cal (IT) to BTU 6 cal (IT) to BTU 7 cal (IT) to BTU 8 cal (IT) to BTU

Calorie (IT) to BTU (th) Conversion Table

Calorie (IT) (cal (IT))	BTU (th) (BTU)
0.5	0.001985
1	0.003971
2	0.007942
5	0.019855
10	0.03971
15	0.059565
20	0.07942
25	0.099274
50	0.198549
100	0.397098
250	0.992744
500	1.985489
1000	3.970977

BTU (th) to Calorie (IT) Conversion Table

BTU (th) (BTU)	Calorie (IT) (cal (IT))
0.5	125.913586
1	251.827171
2	503.654342
5	1,259.135856
10	2,518.271711
15	3,777.407567
20	5,036.543422
25	6,295.679278
50	12,591.358555
100	25,182.717111
250	62,956.792777
500	125,913.585555
1000	251,827.171109

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Calorie (IT) (cal (IT))

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

BTU (th) (BTU)

Energy

Exact conversion

The International Table BTU is exactly 1055.055 852 62 J.

Thermochemical and 39 °F BTU definitions differ by up to 0.2 %.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Calorie (IT) to BTU (th)

To convert from Calorie (IT) (cal (IT)) to BTU (th) (BTU), multiply the value by 0.0039709774.

Formula: BTU = cal (IT) × 0.0039709774

Reverse: cal (IT) = BTU × 251.8271711092

Step-by-Step Example

Start with your value in Calorie (IT). For example: 5 cal (IT)
Multiply by the conversion factor: 5 x 0.0039709774
The result is: 0.019855 BTU

About Calorie (IT)

The calorie (it) (cal (IT)) is a unit of energy and work. One calorie (it) equals 4.1868 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

About BTU (th)

The btu (th) (BTU) is a unit of energy and work. One btu (th) equals 1054.35 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

Frequently Asked Questions

How many BTU (th) are in 1 Calorie (IT)?

There are exactly 0.0039709774 BTU (th) in 1 Calorie (IT). This means the conversion factor from Calorie (IT) to BTU (th) is 0.0039709774.

What is the formula to convert Calorie (IT) to BTU (th)?

The formula to convert Calorie (IT) to BTU (th) is: BTU = cal (IT) × 0.0039709774. For example, to convert 10 Calorie (IT) to BTU (th), you would multiply 10 by 0.0039709774.

What is a Calorie (IT)?