Convert torque between Nm and ft-lb fast, then see both the exact result and a rounded wrench setting you can actually use.
Advanced options
How to use our Nm to ft-lbs Converter Calculator
- Choose Convert from to tell the calculator whether your starting value is in newton-meters or foot-pounds.
- Enter the amount in Torque value, then choose a step in Round wrench setting to if you want a nearby practical setting.
- Open the optional display controls if needed and set Number style or Decimals to show for cleaner output.
- Click Calculate and read Converted torque first, then Rounded wrench setting if you need a wrench-friendly value.
- Sanity-check the answer by looking at Conversion factor used and Formula used; 100 Nm should come out to about 73.76 ft-lb, and 100 ft-lb should come out to about 135.58 Nm.
Definitions
Newton-meter (Nm): A metric torque unit.
Foot-pound (ft-lb): A US-style torque unit based on pound-force and feet. It is often written as ft-lb, lb-ft, or foot-pounds.
Torque value: The starting torque amount you enter before conversion.
Converted torque: The exact torque after changing to the other unit.
Rounded wrench setting: The converted result rounded to the step you chose so it is easier to set on a wrench.
Conversion factor used: The multiplier or divisor applied in the selected direction.
Note: A short message showing whether the rounded setting is above, below, or exactly equal to the exact converted value.
Decimals to show: How many digits appear after the decimal point in the displayed result.
Common mistakes and quick fixes
Mistake: Picking the wrong unit in Convert from and then typing a value from the other system.
Fix: Match Convert from to the unit printed on your spec sheet before entering Torque value .
Mistake: Leaving Torque value blank or pasting text that is not a real number.
Fix: Enter a numeric Torque value only. Decimals are fine, and pasted commas or spaces should still represent one valid number.
Mistake: Using Rounded wrench setting as if it were the exact conversion.
Fix: Use Converted torque for the precise value, and use Rounded wrench setting only when your wrench needs a nearby dial setting.
Mistake: Choosing too much rounding in Round wrench setting to and missing the target by more than you expect.
Fix: If the rounded value looks too coarse, switch Round wrench setting to to Nearest 0.1 or No rounding and compare the Note .
Mistake: Ignoring the sign on a negative Torque value .
Fix: Keep the sign if your use case tracks rotation direction. The sign is preserved in Converted torque and Rounded wrench setting .
Mistake: Thinking Conversion factor used should stay the same both ways.
Fix: It changes with direction. Nm to ft-lb uses about 0.737562149 per Nm, while ft-lb to Nm uses 1.355818 per ft-lb.
Limitations & Key Assumptions / Boundary Conditions
- This calculator converts torque units only. It does not tell you the correct torque spec for your vehicle, tool, or fastener.
- The result depends on the selected direction in Convert from. If that choice is wrong, every output will be wrong.
- Rounded wrench setting is a convenience value, not the exact conversion. Any rounding changes the target torque slightly.
- Display settings such as Number style and Decimals to show affect formatting, not the underlying conversion math.
- Very small floating-point differences can happen inside digital calculations, but the displayed result is cleaned to remove tiny noise.
- Negative values are allowed because some engineering uses track torque direction, but many everyday wrench specs are given as positive magnitudes.
Methodology
Core conversion
The calculator converts the entered torque into the opposite unit and keeps the sign the same. If you enter Nm, it converts to ft-lb. If you enter ft-lb, it converts to Nm.
ft-lb = Nm / 1.355818
Nm = ft-lb * 1.355818
The reciprocal factor for Nm to ft-lb is about 0.737562149, so multiplying by 0.737562149 gives the same result as dividing by 1.355818 [3].
Rounded wrench setting
If you choose a rounding step other than zero, the calculator also gives a nearby practical setting in the result unit.
rounded = round(converted / step) * step
difference = rounded - converted
If the difference is positive, the rounded setting is above the exact value. If it is negative, the rounded setting is below the exact value. If the step is 0, the rounded-setting note is omitted because no rounding is applied.
Mini example
Example: convert 100 Nm to ft-lb with rounding to the nearest 1. First compute the exact conversion.
ft-lb = 100 / 1.355818 = 73.7562149
Then round to the nearest whole ft-lb.
rounded = round(73.7562149 / 1) * 1 = 74
The rounded setting is 74 ft-lb, which is slightly above the exact converted torque.
Display and validation
The calculator accepts decimals and strips commas or spaces before parsing. Blank values, non-numeric text, NaN, and Infinity are rejected as errors. Zero stays zero in either unit, and negative torque remains negative after conversion.
Assumptions used
The conversion uses the standard factor 1 ft-lb = 1.355818 Nm [2]. The broader derivation depends on the exact international foot value of 0.3048 m per ft [2]. Results are intended for unit conversion and practical wrench-setting help, not for replacing manufacturer torque procedures.