Foot Lbs Calculator
Calculate torque in foot-pounds, convert inch-pounds to ft-lbs, or convert Newton-meters to ft-lbs.
What is a Foot-Pound (ft-lb)?
A foot-pound (often written as ft-lb or foot lbs) is commonly used to describe torque. In practical terms, torque is rotational force. If you apply one pound of force at the end of a one-foot wrench, you generate one foot-pound of torque.
You will see ft-lbs used in automotive repair, bike maintenance, machinery setup, and any task involving proper bolt tightening. Using the correct torque helps prevent stripped threads, broken fasteners, and loose components.
How to Use This Foot Lbs Calculator
- Select the calculation type from the dropdown.
- Enter the required value(s) in the input field(s).
- Click Calculate to get the result instantly.
- Use Clear to reset all fields.
Formulas Used
1) Torque from force and distance
ft-lbs = pounds force × feet of lever arm
Example: 40 lbs applied at 1.5 ft = 60 ft-lbs.
2) Convert inch-pounds to foot-pounds
ft-lbs = in-lbs ÷ 12
Example: 240 in-lbs = 20 ft-lbs.
3) Convert Newton-meters to foot-pounds
ft-lbs = N·m × 0.737562149
Example: 100 N·m ≈ 73.76 ft-lbs.
4) Convert foot-pounds to Newton-meters
N·m = ft-lbs × 1.355817948
Example: 75 ft-lbs ≈ 101.69 N·m.
Quick Reference Table
| Unit | Convert To | Formula |
|---|---|---|
| in-lbs | ft-lbs | in-lbs ÷ 12 |
| ft-lbs | in-lbs | ft-lbs × 12 |
| N·m | ft-lbs | N·m × 0.737562149 |
| ft-lbs | N·m | ft-lbs × 1.355817948 |
Why Accurate Torque Matters
Proper torque application ensures clamping force is correct. Too little torque can cause parts to loosen due to vibration. Too much torque can stretch or damage bolts, gaskets, and mating surfaces. A reliable foot pound calculator, combined with a calibrated torque wrench, helps you hit specifications safely and consistently.
Common Mistakes to Avoid
- Confusing in-lbs with ft-lbs (12 in-lbs = 1 ft-lb).
- Using the wrong wrench scale or wrong unit setting.
- Ignoring manufacturer torque sequence on multi-bolt parts.
- Applying dry torque values to lubricated threads without checking specifications.
FAQ
Is ft-lb the same as lb-ft?
Yes. In everyday use they refer to the same torque unit, though formatting may vary by manual or tool brand.
Can I use this for car lug nuts?
Yes. Most lug nut specs are listed in ft-lbs. Just enter the target value when converting units and verify with your vehicle’s service manual.
Does this calculator work for metric torque specs?
Yes. Use the N·m conversion mode to move between metric and imperial torque units.