Torque Calculator Options
Choose a mode, enter values, then convert to your preferred unit.
Example Data
Typical uses across conversion and calculation modes.
| Mode | Input | To Unit | Sample Output |
|---|---|---|---|
| convert | 10 N·m | lbf·ft | ≈ 7.3756 |
| force_distance | 200 N × 0.30 m | N·m | 60.0000 |
| force_distance | 50 lbf × 8 in | lbf·in | 400.0000 |
| power_rpm | 2.2 kW @ 1450 RPM | N·m | ≈ 14.4987 |
| convert | 120 N·cm | lbf·in | ≈ 10.6213 |
Formula Used
How to Use This Calculator
- Select a calculation mode at the top of the form.
- Enter values required for that mode and choose units.
- Select your target torque unit in the “To Unit” field.
- Adjust decimals, rounding, and notation if needed.
- Enable “Worked Steps” to see transparent math.
- Press “Calculate” to show the result above the form.
- Use “All Unit Outputs” for a full comparison table.
- Export or clear your history using the buttons.
Torque Conversion Notes for Practical Work
1) What a Newton Meter Represents
Torque is a turning effect produced by a force acting at a distance. In SI terms, one Newton meter equals one Newton applied at a one‑meter radius. In maintenance work, torque helps control clamp load on bolts and prevents joint slip, fatigue, or thread damage.
2) Common Units You Will Meet
Workshop charts often mix N·m with lbf·ft and lbf·in. Smaller fasteners are commonly specified in lbf·in or N·cm, while drivetrain and wheel hardware is usually in lbf·ft or N·m. This calculator includes kgf·m, kgf·cm, and dyne‑cm for legacy and lab references.
3) Typical Torque Ranges by Application
Light assemblies such as electronics enclosures may use 0.2–2 N·m. Bicycle stems and seat clamps often fall near 4–12 N·m. Passenger car wheel nuts are frequently in the 80–140 N·m range, while larger commercial hardware can exceed 400 N·m depending on size and grade.
4) Why Conversion Precision Matters
A small rounding change can be meaningful when a specification is tight. For example, converting 10 N·m to lbf·in yields about 88.51 lbf·in, so rounding to 89 lbf·in may be fine for general service, but not for calibration paperwork. Use decimal places and scientific notation for audit‑ready logs.
5) Using Force × Distance Mode
When you know the applied force and the lever arm, use τ = F × r. The optional sin(θ) factor is useful if the force is not perpendicular to the lever arm. At 30°, sin(30°)=0.5, meaning only half the force contributes to torque.
6) Using Power & RPM Mode
For rotating machines, torque relates to power by τ = P/ω, where ω = 2π×RPM/60. At constant power, lower RPM means higher torque. This is helpful when comparing motor and gearbox setups, or validating datasheets across kW, hp, and shaft speed.
7) Quick Reference Conversions
A practical mental check: 1 lbf·ft ≈ 1.356 N·m, and 1 N·m ≈ 0.7376 lbf·ft. For inch units, 1 lbf·in ≈ 0.1130 N·m, and 1 N·m ≈ 8.8507 lbf·in. These align with the unit factors used here.
8) Good Workflow for Documentation
Select the calculation mode, confirm units, then set formatting. Enable Worked Steps for traceability. Use the all‑unit table to cross‑check values, then export CSV for spreadsheets or PDF for job packs. Keeping the base N·m value in history supports later verification.
FAQs
1) Is N·m the same as Joule?
They share the same SI dimensions, but they describe different concepts. N·m is torque (rotational), while Joule is energy. Treat the “J” label as a reference, not a replacement for torque units.
2) Which unit should I use for small screws?
Use lbf·in, N·cm, or N·mm for low‑torque fasteners. These units provide finer numeric resolution and reduce rounding error compared with lbf·ft or kN·m.
3) What does the angle option change?
It applies sin(θ) when the force is not perpendicular to the lever arm. At 90° the factor is 1.0, and at 0° it is 0, meaning no turning effect is produced.
4) Why does my converted value differ from a chart?
Differences usually come from rounding, unit definitions, or chart truncation. Increase decimals, switch rounding to “Nearest,” and compare against the base N·m value to confirm consistency.
5) What is the fastest sanity check?
Use 1 N·m ≈ 0.7376 lbf·ft or 1 lbf·ft ≈ 1.356 N·m. If your result is far off these ratios, verify that the input and output units are set correctly.
6) Can I export only the last result?
Exports include the recent history stored in your session. If you want only one line, clear history, run a single calculation, then download CSV or PDF for a clean one‑row report.
7) Does this work offline?
The calculator is a single PHP file, but it loads a CSS/JS library from a CDN. If you need offline use, download those assets locally and update the link tags to point to your local files.