Calorie/Second to BTU/Second Converter

Power Converter

22 units available

Decimals:

From

To

0.003966

1 cal/s = 0.003966 BTU/s

Formula:

BTU/s = cal/s × 0.0039656668

With your value: 1 cal/s = 0.00396567 BTU/s

How big is that?

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

Your value1.00 cal/s

LED bulb (2.2× your value)2.15 cal/s

Laptop (16× your value)15.5 cal/s

Microwave oven (2.4e+2× your value)239 cal/s

Electric kettle (7.2e+2× your value)717 cal/s

Family car engine (2.2e+4× your value)2.15e+4 cal/s

Other Calorie/Second to BTU/Second conversions

2 cal/s to BTU/s 3 cal/s to BTU/s 4 cal/s to BTU/s 5 cal/s to BTU/s 6 cal/s to BTU/s 7 cal/s to BTU/s 8 cal/s to BTU/s

Calorie/Second to BTU/Second Conversion Table

Calorie/Second (cal/s)	BTU/Second (BTU/s)
0.5	0.001983
1	0.003966
2	0.007931
5	0.019828
10	0.039657
15	0.059485
20	0.079313
25	0.099142
50	0.198283
100	0.396567
250	0.991417
500	1.982833
1000	3.965667

BTU/Second to Calorie/Second Conversion Table

BTU/Second (BTU/s)	Calorie/Second (cal/s)
0.5	126.0822
1	252.164401
2	504.328801
5	1,260.822004
10	2,521.644007
15	3,782.466011
20	5,043.288014
25	6,304.110018
50	12,608.220036
100	25,216.440072
250	63,041.10018
500	126,082.200361
1000	252,164.400722

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/Second (cal/s)

Power

Exact conversion

Derived from the watt (1 W = 1 J/s).

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/Second (BTU/s)

Power

Exact conversion

Derived from the watt (1 W = 1 J/s).

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/Second to BTU/Second

To convert from Calorie/Second (cal/s) to BTU/Second (BTU/s), multiply the value by 0.0039656668.

Formula: BTU/s = cal/s × 0.0039656668

Reverse: cal/s = BTU/s × 252.1644007218

Step-by-Step Example

Start with your value in Calorie/Second. For example: 5 cal/s
Multiply by the conversion factor: 5 x 0.0039656668
The result is: 0.019828 BTU/s

About Calorie/Second

The calorie/second (cal/s) is a unit of power. One calorie/second equals 4.184 watts. UnitConvertLab converts it against every other power unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

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

About BTU/Second

The btu/second (BTU/s) is a unit of power. One btu/second equals 1055.055853 watts. UnitConvertLab converts it against every other power unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

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

Frequently Asked Questions

How many BTU/Second are in 1 Calorie/Second?

There are exactly 0.0039656668 BTU/Second in 1 Calorie/Second. This means the conversion factor from Calorie/Second to BTU/Second is 0.0039656668.

What is the formula to convert Calorie/Second to BTU/Second?

The formula to convert Calorie/Second to BTU/Second is: BTU/s = cal/s × 0.0039656668. For example, to convert 10 Calorie/Second to BTU/Second, you would multiply 10 by 0.0039656668.

What is a Calorie/Second?