Formula: foot-pounds to newton-meters
N·m = ft·lb × 1.3558179483
Example: 25 ft·lb × 1.3558179483 ≈ 33.895 N·m
Formula: newton-meters to foot-pounds
ft·lb = N·m ÷ 1.3558179483
Example: 40 N·m ÷ 1.3558179483 ≈ 29.502 ft·lb
Torque vs energy note
Both torque and work/energy can be written as “ft·lb” or “N·m”. The numbers are the same for unit conversion, but in context you should say “ft·lb of torque” or “foot-pounds of energy”. This page does the numeric conversion only.
FAQ
1. Why 1.3558179 and not just 1.36?
1.36 is fine for quick estimates, but engineering specs often need more precision, so we keep the factor tied to the exact definition of the foot and the pound-force.
2. How do I go from in·lb to N·m?
First convert in·lb → ft·lb (divide by 12), then ft·lb → N·m. Or use the shortcut 1 in·lb = 0.113 N·m (approx 0.1130).
3. Can I use this for torque wrench settings?
Yes. Read the value in ft·lb or N·m from your procedure, convert here, then set the wrench to the converted unit.
Formula (LaTeX) + variables + units
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N·m = ft·lb × 1.3558179483 Example: 25 ft·lb × 1.3558179483 ≈ 33.895 N·m
ft·lb = N·m ÷ 1.3558179483 Example: 40 N·m ÷ 1.3558179483 ≈ 29.502 ft·lb
- No variables provided in audit spec.
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units
Last code update: 2026-01-19
- Initial audit spec draft generated from HTML extraction (review required).
- Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
- Confirm sources are authoritative and relevant to the calculator methodology.