Force Unit Converter
Convert N, dyne, kgf, lbf, ozf, and kip with exact factors.
What it does
Force conversion is multiplication by a fixed factor through the newton. The newton anchors the SI side as one kilogram meter per second squared, and the pound-force anchors the imperial side at exactly 4.4482216152605 N. Every other unit follows from those definitions.
The tool above converts between six units: newtons, dynes, kilograms-force, pounds-force, ounces-force, and kips. Pick the source and target, enter the value, and the answer updates at once, with all six equivalents listed below it. The default 10 lbf reads 44.4822 N.
NIST publishes every factor used here. Its conversion appendix lists the dyne at 1.0E-05 N, the kilogram-force at exactly 9.80665 N, and the pound-force at 4.448222 N in short display of the exact figure. The BIPM SI Brochure carries the newton and standard gravity behind them.
Bench habits close the page. Convert through newtons for chains across systems instead of memorizing pair ratios, and round only the printed answer. Mass units (kg, lb) are not force units (kgf, lbf): weight needs gravity in the step.
How to use
- Enter the value in the source unit.
- Pick the source unit on the left and the target on the right.
- Read the converted line first.
- Scan the all units note for the rest.
- Round only the final number, never mid chain.
- Use kip for structural loads and dyne for small lab forces.
Formula
- N
- The SI base: 1 kg m/s2.
- dyne 1e-5
- Exact CGS to SI step.
- kgf 9.80665
- Exact: standard gravity times one kilogram.
- lbf 4.44822
- Exact: 0.45359237 kg times standard gravity.
The lbf factor is exact from 0.45359237 kg times standard gravity 9.80665 m/s2. The kgf factor is exactly 9.80665 N per BIPM and NIST.
Worked example
Example: 10 lbf to newtons
Defaults: 10 lbf to newtons.
- Inputs: value 10, from pounds-force, to newtons.
- Base: 10 x 4.4482216152605 = 44.482216152605 N.
- Target matches base here, so result is 44.4822 N.
- Cross check: 10 lbf is 4.5359 kgf (44.4822 / 9.80665).
- Tool shows 44.4822 N with all six equivalents in the note.
Reference table
| Pair | Factor | Everyday check |
|---|---|---|
| 1 lbf to N | 4.4482216152605 (exact) | 10 lbf is 44.4822 N |
| 1 kgf to N | 9.80665 (exact) | 5 kgf is 49.0332 N |
| 1 N to lbf | 0.22480894 | 100 N is 22.4809 lbf |
| 1 dyne to N | 0.00001 (exact) | 250,000 dyne is 2.5 N |
| 1 kip to N | 4448.2216152605 | 1 kip is 1000 lbf |
Limits
- Unit math only. Mass versus weight context stays with the user.
- Ounce-force uses the avoirdupois ounce; troy differs.
- Poundal omitted; convert via 0.138255 N when needed.
- Rounding mid chain across systems drifts results.
Common mistakes
- Reading pounds of mass as pounds of force.
- Using 4.45 for the lbf and drifting on big loads.
- Rounding mid chain instead of once at the end.
- Mixing troy and avoirdupois ounces.
- Trusting a rounded factor from memory for precision work.
Try it yourself
Quick checks. Answers sit tucked under each question.
5 kgf to newtons?
5 x 9.80665 = 49.03325 N, shown as 49.0332 N.
100 N to lbf?
100 / 4.4482216152605 = 22.4809 lbf.
Questions
What is the base unit?
The newton (N): one kilogram meter per second squared. All units pass through it here.
How do I convert lbf to N?
Multiply by 4.4482216152605 exactly. So 10 lbf is 44.4822 N.
How do I convert kgf to N?
Multiply by 9.80665 exactly, the standard gravity figure. So 5 kgf is 49.0332 N.
Dyne versus newton: what differs?
They differ by definition: the dyne is CGS (1e-5 N) while the newton is SI. Use dyne for small lab forces.
What is a kip?
A thousand pounds-force: 4,448.2216152605 N. Structural loads often read in kips.
How do I convert N back to lbf?
Divide by 4.4482216152605. So 100 N is 22.4809 lbf.
Sources
- NIST Guide to the SI, Appendix B.8 (alphabetical factors)
- NIST Guide to the SI, Appendix B.9 (factors by quantity)
- BIPM: SI Brochure