BTU/Second to Milliwatt Converter

Power Converter

22 units available

Decimals:

From

To

1,055,055.85262

1 BTU/s = 1,055,055.85262 mW

Formula:

mW = BTU/s × 1,055,055.85262

With your value: 1 BTU/s = 1,055,055.85262 mW

How big is that?

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

LED bulb (1/1.2e+2 your value)0.00853 BTU/s

Laptop (1/16 your value)0.0616 BTU/s

Microwave oven (1/1.1 your value)0.948 BTU/s

Your value1.00 BTU/s

Electric kettle (2.8× your value)2.84 BTU/s

Family car engine (85× your value)85.3 BTU/s

Other BTU/Second to Milliwatt conversions

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

BTU/Second to Milliwatt Conversion Table

BTU/Second (BTU/s)	Milliwatt (mW)
0.5	527,527.92631
1	1,055,055.85262
2	2,110,111.70524
5	5,275,279.2631
10	10,550,558.5262
15	15,825,837.7893
20	21,101,117.0524
25	26,376,396.3155
50	52,752,792.631
100	105,505,585.262
250	263,763,963.155
500	527,527,926.31
1000	1,055,055,852.62

Milliwatt to BTU/Second Conversion Table

Milliwatt (mW)	BTU/Second (BTU/s)
0.5	4.739086e-7
1	9.478171e-7
2	1.895634e-6
5	4.739086e-6
10	9.478171e-6
15	1.421726e-5
20	1.895634e-5
25	2.369543e-5
50	4.739086e-5
100	9.478171e-5
250	0.000237
500	0.000474
1000	0.000948

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.

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

Milliwatt (mW)

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 BTU/Second to Milliwatt

To convert from BTU/Second (BTU/s) to Milliwatt (mW), multiply the value by 1,055,055.85262.

Formula: mW = BTU/s × 1,055,055.85262

Reverse: BTU/s = mW × 9.478171e-7

Step-by-Step Example

Start with your value in BTU/Second. For example: 5 BTU/s
Multiply by the conversion factor: 5 x 1,055,055.85262
The result is: 5,275,279.2631 mW

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.

About Milliwatt

The milliwatt (mW) is a unit of power. One milliwatt equals 0.001 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 Milliwatt are in 1 BTU/Second?

There are exactly 1,055,055.85262 Milliwatt in 1 BTU/Second. This means the conversion factor from BTU/Second to Milliwatt is 1,055,055.85262.

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

The formula to convert BTU/Second to Milliwatt is: mW = BTU/s × 1,055,055.85262. For example, to convert 10 BTU/Second to Milliwatt, you would multiply 10 by 1,055,055.85262.

What is a BTU/Second?