Nm to ft-lb
Convert torque specs from newton meters to foot-pounds.
Category
Engineering Converters
Pressure and practical engineering conversion tools with short explanations and quick reference tables.
Last updated: June 2026
Engineering and workshop tasks lean on a small set of conversions where getting the unit wrong has real consequences. A torque figure in the wrong unit can over-tighten a bolt, a fan rated in an unfamiliar airflow unit can be undersized for a room, and a pressure gauge in bar means little when the spec sheet is in PSI. The tools here give the exact figure plus a short note on where each unit is used, so a European spec and a US one line up.
Torque and pressure are the two that catch people out most. A torque in newton meters (Nm) and the same torque in foot-pounds (ft-lb) are close enough in size that a slip between them is easy to miss, but large enough to matter on a tight fastener.
Tools in this section
Ft-lb to Nm
Convert torque from foot-pounds to newton meters for metric tools.
CFM to m³/h
Convert airflow between CFM and cubic meters per hour for fans and ventilation.
Watts to HP
Convert motor and engine power from watts to horsepower.
Bar to PSI
Convert pressure between bar and PSI for gauges and compressors.
Common engineering conversion factors
The conversions behind the tools above, with the multiplier and a worked example for each. Torque and pressure are the two where a unit slip does real damage.
| Conversion | Factor | Worked example |
|---|---|---|
| Nm to ft-lb | × 0.7376 | 40 Nm = 29.5 ft-lb |
| ft-lb to Nm | × 1.3558 | 30 ft-lb = 40.7 Nm |
| bar to PSI | × 14.504 | 2.5 bar = 36.3 PSI |
| PSI to bar | × 0.06895 | 32 PSI = 2.2 bar |
| CFM to m³/h | × 1.699 | 100 CFM = 169.9 m³/h |
| Watts to HP | ÷ 745.7 | 1500 W = 2.0 HP |
Which unit system to expect in each engineering context
The unit you see depends heavily on where a machine was made and what industry it came from. European manufacturers almost always spec torque in newton meters and pressure in bar. American manufacturers use foot-pounds for torque and PSI for pressure. Japanese manufacturers typically use Nm for torque but may list pressure in kPa. Reading a service manual from the wrong region and using the figures directly is the most common source of over-tightened fasteners in workshop repair.
Pressure units are even more fragmented. Tyre labels print PSI in the US, bar in Europe, and kPa in Australia and parts of Asia. Industrial compressors, hydraulic systems and pneumatic tools each have their own regional defaults. A quick rule: 1 bar is close to 14.5 PSI, and 100 kPa equals 1 bar exactly.
Airflow is where ventilation sizing goes wrong. Extractor fans sold in Europe are rated in m³/h; North American fans use CFM. A bathroom fan at 110 CFM is roughly 187 m³/h, meaning the same product at the same airflow can look like a completely different number depending on the label. Horsepower in motor specs is another split: metric HP (PS) and mechanical HP differ by about 1.4 percent, small enough to ignore in most workshop contexts but relevant when comparing European and American motor specs directly.
Frequently Asked Questions
How do I convert a torque spec from Nm to ft-lb?
Multiply the newton meter figure by 0.7376. So 40 Nm is about 29.5 ft-lb and 100 Nm is about 73.8 ft-lb. To go the other way, multiply foot-pounds by 1.356.
Why does it matter which torque unit I use?
Because the numbers are close but not equal, mixing them up over- or under-tightens a fastener. A bolt specified at 40 Nm tightened to 40 ft-lb is actually at 54 Nm, well over spec, which can strip a thread or crack a casting.
What is the difference between CFM and m³/h for airflow?
Both measure volume of air moved over time; CFM is cubic feet per minute and m³/h is cubic meters per hour. One CFM is about 1.7 m³/h, so a fan rated 100 CFM moves roughly 170 m³/h. Fans and extractors are labelled in one or the other depending on region.
How do I convert watts to horsepower?
Divide watts by 745.7 for mechanical horsepower. So a 1500 W motor is about 2 HP. Note that motors are sometimes rated in input watts and sometimes in output power, so compare like with like.
Is bar the same as PSI?
No. One bar is about 14.5 PSI, so a 2.5 bar tyre is about 36 PSI. Bar is common on European equipment and PSI on US gauges, which is why a single compressor often shows both scales.