Work from one pound-force over one foot.
Foot-pounds to Millijoules Converter — ft-lb to mJ
Convert Foot-pound (ft-lb) to Millijoule (mJ) using the exact conversion factor (1 foot-pound = 1,355.817948 millijoule). See the formula, worked examples, and conversion table.
Foot-pounds to Millijoules 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.
Millijoule is 0.001 joule units.
Result = input x 1.355817948 / 0.001.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Foot-pounds to Millijoules
Foot-pound and Millijoule 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: Work from one pound-force over one foot, and millijoule is 0.001 joule units.
Formula
millijoules = foot-pounds × 1355.81794833
This factor comes from each unit's defined relationship to the category's base unit: 1 foot-pound equals 1.35581794833 base units, and 1 millijoule equals 0.001 base units, so dividing one by the other gives the direct foot-pound-to-millijoule factor of 1355.81794833.
Simple example
1 ft-lb × 1355.817948 = 1,355.817948 mJ
1 foot-pound = 1,355.817948 millijoules.
Real-world example
100 ft-lb × 1355.817948 = 135,581.7948 mJ
100 foot-pounds = 135,581.7948 millijoules.
Conversion table
| Foot-pound (ft-lb) | Millijoule (mJ) |
|---|---|
| 1 ft-lb | 1,355.817948 mJ |
| 10 ft-lb | 13,558.17948 mJ |
| 50 ft-lb | 67,790.89742 mJ |
| 100 ft-lb | 135,581.7948 mJ |
| 500 ft-lb | 677,908.9742 mJ |
| 1,000 ft-lb | 1,355,817.948 mJ |
Reverse conversion: Millijoule to Foot-pound
1 mJ × 0.0007375621493 = 0.0007375621 ft-lb
1 millijoule = 0.0007375621 foot-pounds.
foot-pounds = millijoules × 0.000737562149277
For a page dedicated to this direction, see Millijoule to Foot-pound.
Understanding the Foot-pound (ft-lb)
Work from one pound-force over one foot.
Understanding the Millijoule (mJ)
Millijoule is 0.001 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many millijoules are in 1 foot-pound?
1 foot-pound equals 1,355.817948 millijoules, using the exact defined conversion factor rather than an estimate.
How do I convert foot-pound to millijoule?
Multiply the foot-pound value by 1355.817948. The converter above does this instantly to whatever precision you set.
How do I convert millijoule back to foot-pound?
Use the reverse factor: 1 millijoule equals 0.0007375621 foot-pounds. You can also use the swap control in the converter above to flip the direction instantly.
What is a foot-pound?
Foot-pound (ft-lb) is a unit of engineering.
What is a millijoule?
Millijoule (mJ) is a unit of engineering.
Is the foot-pound to millijoule conversion exact?
Yes. Both foot-pound and millijoule are defined by fixed standards rather than physical artifacts, so the factor of 1355.817948 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.