Convert BTU per hour to Milliwatts
1 BTU per hour is 293.07 mW. One BTU per hour is exactly 293.071070172 milliwatts.
One BTU per hour is 293.07107 milliwatts. To convert BTU per hour to milliwatts, multiply by 293.07107; to go the other way, divide by 293.07107 or multiply by 0.0034121416. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Special Publication 811. The rate US heating and air conditioning is sold in.
Factor checked against the defining standard · How we check
- BTU per hour × 293.07107
1 * 293.07107293.071 mW
1 BTU per hour in every power unit
| Unit | Value | Exact factor |
|---|---|---|
| horsepower | 0.0003930147789 hp | × 0.000393014778922 |
| metric horsepower | 0.0003984657624 PS | × 0.000398465762413 |
| watts | 0.2930710702 W | × 0.293071070172 |
| kilowatts | 0.0002930710702 kW | × 0.000293071070172 |
| milliwatts | 293.0710702 mW | × 293.071070172 |
| megawatts | 0.0000002930710702 MW | × 0.000000293071070172 |
| tons of refrigeration | 0.00008333333333 TR | × 0.0000833333333333 |
| BTU per hour (as entered) | 1 BTU/h | — |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert BTU per hour to milliwatts? The converter and the working
- 1.Take the measurement in BTU per hour.
- 2.Multiply by 293.07107 — that is how many milliwatts fit in one BTU per hour.
- 3.To go back the other way, divide by 293.07107, or multiply by 0.0034121416.
Worked example: 25 BTU per hour to milliwatts
- Formula
- BTU/h × 293.07107 = mW
- Arithmetic
- 25 × 293.07107 = 7,326.78 mW
- Answer
- 25 BTU/h = 7,326.78 mW
The factor is rounded for display; the figure above is computed from the full value.
BTU per hour to milliwatts conversion table
| BTU per hour | Milliwatts |
|---|---|
| 1 BTU/h | 293.07 mW |
| 2 BTU/h | 586.14 mW |
| 3 BTU/h | 879.21 mW |
| 4 BTU/h | 1,172.28 mW |
| 5 BTU/h | 1,465.36 mW |
| 6 BTU/h | 1,758.43 mW |
| 7 BTU/h | 2,051.5 mW |
| 8 BTU/h | 2,344.57 mW |
| 9 BTU/h | 2,637.64 mW |
| 10 BTU/h | 2,930.71 mW |
| 12 BTU/h | 3,516.85 mW |
| 15 BTU/h | 4,396.07 mW |
| 20 BTU/h | 5,861.42 mW |
| 25 BTU/h | 7,326.78 mW |
| 50 BTU/h | 14,653.55 mW |
| 100 BTU/h | 29,307.11 mW |
| 200 BTU/h | 58,614.21 mW |
| 300 BTU/h | 87,921.32 mW |
| 500 BTU/h | 146,535.54 mW |
| 1000 BTU/h | 293,071.07 mW |
| 2000 BTU/h | 586,142.14 mW |
| 5000 BTU/h | 1,465,355.35 mW |
| 10000 BTU/h | 2,930,710.7 mW |
What is a BTU per hour?
The rate US heating and air conditioning is sold in. A 12,000 BTU/h unit is one "ton" of cooling and about 3.5 kilowatts of heat moved.
What is a milliwatt?
A thousandth of a watt. Radio transmit power, laser output and audio signal levels are all quoted in it, and dBm is referenced to exactly one.
How many milliwatts are in a BTU per hour?
One BTU per hour is 293.07107 milliwatts. Going the other way, one milliwatt is 0.0034121416 BTU per hour. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every power unit here
The whole group — 8 units with their symbols and the size of each one in watts — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a BTU per hour.
Source: NIST Special Publication 811 — mechanical horsepower is 550 ft·lbf/s exactly
Cite this page
- APA
- Rule Calculator. (2026). Convert BTU per hour to milliwatts. Rule Calculator. https://rulecalculators.com/convert/btu-per-hour-to-milliwatt
- MLA
- "Convert BTU per hour to milliwatts." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/btu-per-hour-to-milliwatt.
- Chicago
- Rule Calculator. "Convert BTU per hour to milliwatts." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/btu-per-hour-to-milliwatt.
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Questions people actually ask
- How many milliwatts are in a BTU per hour?
- 293.07107. A thousandth of a watt. Radio transmit power, laser output and audio signal levels are all quoted in it, and dBm is referenced to exactly one.
- How do I convert milliwatts back to BTU per hour?
- Divide by 293.07107, or multiply by 0.0034121416 — they are the same operation.
Other power conversions
Milliwatts to BTU per hour — the same conversion the other way.