Femtowatt is 1e-15 watt units.
Femtowatts to BTU per hour Converter — fW to BTU/h
Convert Femtowatt (fW) to BTU per hour (BTU/h) using the exact conversion factor (1 femtowatt = 3.412142e-15 btu per hour). See the formula, worked examples, and conversion table.
Femtowatts to BTU per hour converter
Converter
Engineering Converter
Convert common stress, force, torque, power, and energy units used in engineering.
Context values
Some unit families need one extra value for a physically accurate result.
Power rate using BTU per hour.
Result = input x 1e-15 / 0.2930710702.
Power units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Femtowatts to BTU per hour
Femtowatt and BTU per hour both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. Specifically: Femtowatt is 1e-15 watt units, and power rate using BTU per hour.
Formula
btu per hour = femtowatts × 3.412142e-15
This factor comes from each unit's defined relationship to the category's base unit: 1 femtowatt equals 1e-15 base units, and 1 btu per hour equals 0.293071070172 base units, so dividing one by the other gives the direct femtowatt-to-btu per hour factor of 3.412142e-15.
Simple example
1 fW × 3.412142e-15 = 3.412142e-15 BTU/h
1 femtowatt = 3.412142e-15 btu per hour.
Real-world example
100 fW × 3.412142e-15 = 3.412142e-13 BTU/h
100 femtowatts = 3.412142e-13 btu per hour.
Conversion table
| Femtowatt (fW) | BTU per hour (BTU/h) |
|---|---|
| 1 fW | 3.412142e-15 BTU/h |
| 10 fW | 3.412142e-14 BTU/h |
| 50 fW | 1.706071e-13 BTU/h |
| 100 fW | 3.412142e-13 BTU/h |
| 500 fW | 1.706071e-12 BTU/h |
| 1,000 fW | 3.412142e-12 BTU/h |
Reverse conversion: BTU per hour to Femtowatt
3.412142e-15 BTU/h × 2.930711e+14 = 1.000000108 fW
3.412142e-15 btu per hour = 1.000000108 femtowatts.
femtowatts = btu per hour × 2.930711e+14
For a page dedicated to this direction, see BTU per hour to Femtowatt.
Understanding the Femtowatt (fW)
Femtowatt is 1e-15 watt units.
Understanding the BTU per hour (BTU/h)
Power rate using BTU per hour.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many btu per hour are in 1 femtowatt?
1 femtowatt equals 3.412142e-15 btu per hour, using the exact defined conversion factor rather than an estimate.
How do I convert femtowatt to btu per hour?
Multiply the femtowatt value by 3.412142e-15. The converter above does this instantly to whatever precision you set.
How do I convert btu per hour back to femtowatt?
Use the reverse factor: 1 btu per hour equals 2.930711e+14 femtowatts. You can also use the swap control in the converter above to flip the direction instantly.
What is a femtowatt?
Femtowatt (fW) is a unit of engineering.
What is a btu per hour?
BTU per hour (BTU/h) is a unit of engineering.
Is the femtowatt to btu per hour conversion exact?
Yes. Both femtowatt and btu per hour are defined by fixed standards rather than physical artifacts, so the factor of 3.412142e-15 used above is exact to as many digits as you choose to display.
Why do engineering unit conventions vary so much by region and industry?
Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.