Why is torque (N·m) separate from energy (J)?

They have the same base units but mean different things: torque is a turning effect, energy is work done. The converter keeps them in separate lists so you don't mix them up.

Can I convert compound units like kg/m³ or kN/mm²?

Yes. Use Any unit and type them, for example kN/mm^2 to MPa.

Unit converter

Length, force, pressure, energy, torque, speed, temperature and compound units.

Precision

From

1 m = 3.280839895 ft1 m = 3.280839895 ftExplain with Waypoint Mentor

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How to use it

Pick a quantity (length, pressure, torque, and so on), choose the two units, and type a value on either side. The conversion works both ways: edit the right-hand box and the left one updates.

Search the unit lists by name or symbol, so typing psi or pound finds pounds per square inch.

For anything not in the lists, switch to Any unit and type the units yourself, for example kN m to lbf ft, or kg/m^3 to lb/ft^3. The converter checks the two units measure the same thing, and tells you if they don't (you can't turn metres into seconds).

How the conversion works

Every unit is stored as a multiple of SI base units. A conversion multiplies by the first unit's factor and divides by the second's:

x_{\text{to}} = x_{\text{from}}\,\frac{k_{\text{from}}}{k_{\text{to}}}

For example, $1\ \text{psi} = 6894.757\ \text{Pa}$ and $1\ \text{kPa} = 1000\ \text{Pa}$ , so $30\ \text{psi} = 30 \times 6894.757 / 1000 = 206.8\ \text{kPa}$ .

Temperature is the exception. Celsius and Fahrenheit have offsets as well as scales, so $T_F = \tfrac{9}{5}T_C + 32$ . A temperature difference of $1^\circ\text{C}$ is $1.8^\circ\text{F}$ , not $33.8^\circ\text{F}$ .

Precision

Results show 10 significant figures by default. Use the precision control to round to what your question needs, usually the same number of significant figures as your least precise input.

Worked example: Torque from a spec sheet

A motor's datasheet gives a torque of $2.5$ kN·m, but your wrench reads in lbf·ft. Since $1$ lbf·ft $= 1.3558$ N·m,

2.5\ \text{kN·m} = \frac{2500}{1.3558}\ \text{lbf·ft} \approx 1843.9\ \text{lbf·ft}

Choose Torque, then kN·m to lbf·ft, and type $2.5$ .

Questions

Why is torque (N·m) separate from energy (J)?: They have the same base units but mean different things: torque is a turning effect, energy is work done. The converter keeps them in separate lists so you don't mix them up.
Can I convert compound units like kg/m³ or kN/mm²?: Yes. Use Any unit and type them, for example kN/mm^2 to MPa.

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Lessons

Calculations run on your device with exact, tested maths (no AI). Results are for learning and checking work, not certified engineering design.