BTU/hr to Milliwatts Converter
Enter the power in btu/hr below to convert it to milliwatts.
Convert BTU/hr to Milliwatts
Enter a value in btu/hr (BTU/hr) to convert to milliwatts (mW).
BTU per Hour to Milliwatt Conversion Table
Table showing various btu per hour measurements converted to milliwatts. Click any preset value or arrow to load it into the converter.
| BTU/hr (BTU/hr) | Milliwatts (mW) |
|---|---|
| 1 BTU/hr | 293.07107 mW |
| 2 BTU/hr | 586.14214 mW |
| 2.5 BTU/hr | 732.677675 mW |
| 5 BTU/hr | 1,465.35535 mW |
| 10 BTU/hr | 2,930.7107 mW |
| 15 BTU/hr | 4,396.06605 mW |
| 20 BTU/hr | 5,861.4214 mW |
| 25 BTU/hr | 7,326.77675 mW |
| 30 BTU/hr | 8,792.1321 mW |
| 50 BTU/hr | 14,653.5535 mW |
How to Convert BTU/hr to Milliwatts
To convert btu/hr to milliwatts, multiply the power by the following conversion ratio: 293.07107 milliwatts/btu per hour.
Since one btu per hour is equal to 293.07107 milliwatts, you can use this simple formula to convert:
The power in milliwatts is equal to the power in btu/hr multiplied by 293.07107.
For example, here's how to convert 5 btu/hr to milliwatts using the formula above.
How Many Milliwatts Are in a BTU per Hour?
There are 293.07107 milliwatts in a btu per hour, which is why we use this value in the formula above.
Our btu per hour to milliwatt calculator automatically converts your power measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
BTU/hr and milliwatts are both units used to measure power. Keep reading to learn more about each unit.
What Is a BTU per Hour?
A btu per hour is a unit of power equal to 0.2930711 watts (W), the base unit for power. HVAC thermal rate (1 W ≈ 3.41214 BTU/hr). [1]
The btu per hour is classified as a US customary and imperial unit of power. BTU/hr can be abbreviated as BTU/hr; for example, 1 btu per hour can be written as 1 BTU/hr.
When working with btu/hr (BTU/hr) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, btu/hr (BTU/hr) are widely used across standard power applications within US customary and imperial workflows, engineering documentation, and technical data sheets.
What Is a Milliwatt?
A milliwatt is a unit of power equal to 1/1,000 of a watt (0.001 W). One-thousandth of a Watt. [2]
The milliwatt is classified as a metric and SI-compatible unit of power. Milliwatts can be abbreviated as mW; for example, 1 milliwatt can be written as 1 mW.
In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the milliwatt (mW) a convenient decimal multiple of the watt (W).
In practice, milliwatts (mW) are widely used across fine-tolerance laboratory, analytical, and micro-scale power measurements within SI metric workflows, engineering documentation, and technical data sheets.
When converting power between btu/hr (BTU/hr) and milliwatts (mW), keep full floating-point precision (1 BTU/hr = 293.07107 mW; 1 mW = 0.0034121 BTU/hr) during intermediate calculations and round only the final milliwatt figure to match your instrument tolerance.
More BTU per Hour & Milliwatt Conversions
Need to calculate in the opposite direction? Use our milliwatts to btu/hr calculator to switch your starting unit immediately. You can also explore related tools such as converting milliwatts to btu/hr, converting btu/hr to watts, or converting btu/hr to tons of refrigeration.
Frequently Asked Questions
References
- [1]NIST SP 811 StandardNIST SP 811 (NIST SP 811 App. B.9 (Power & Radiant Flux))·Power Metrology Standard — BTU/hr (BTU/hr) to Milliwatts (mW)
- [2]NIST CUU SpecificationNIST CUU (Derived SI Unit: Watt (W))·Unit Specifications: BTU per Hour (BTU/hr) & Milliwatt (mW)
- [3]BIPM ReferenceBIPM (SI Brochure (9th Ed.) — Power)·Conversion Factors & Mathematical Basis (BTU/hr to mW)