Force Unit Converter
kN, N, tonne-force, kgf and lbf for loads and lifting.
Quick answer
With the default inputs: Value 1 · From unit Kilonewton · To unit Tonne-forceConverted value 0.101972 tf
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Result
Converted value
0.101972tf
| Kilonewton | 1kN |
| Newton | 1000.00N |
| Meganewton | 0.001MN |
| Dekanewton | 100daN |
| Kilogram-force | 101.9716kgf |
| Tonne-force | 0.101972tf |
| Pound-force | 224.809lbf |
| Kip | 0.224809kip |
Conversions use standard gravity, 9.80665 m/s², matching code values. Selection of lifting and support components must be checked by a qualified engineer.
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Formula
| Base | 1 kN = 1000 N, 1 MN = 1000 kN |
| Gravity | 1 kgf = 9.80665 N, 1 tf = 9.80665 kN |
| Anglo-American | 1 lbf = 4.44822 N, 1 kip = 1000 lbf = 4.44822 kN |
| Mass and force | 1 t of mass produces 9.80665 kN of weight |
| Site rule | Take 1 t ≈ 10 kN, a 2% overestimate |
One tonne-force is 9.80665 kN, 1000 kgf or 2204.62 lbf. A sling rated 50 kN is about 5.1 tf; with a safety factor of 6 each leg may lift 0.85 t.
Force and load unit reference
| Unit | Symbol | In kN | In tonne-force | Typical use |
|---|---|---|---|---|
| Kilonewton | kN | 1 | 0.102 | Structural loads |
| Newton | N | 0.001 | 0.000102 | Small members |
| Dekanewton | daN | 0.01 | 0.00102 | European marking |
| Tonne-force | tf | 9.80665 | 1 | Lifting weights |
| Kilogram-force | kgf | 0.009807 | 0.001 | Old codes |
| Kip | kip | 4.44822 | 0.4536 | US structures |
| Pound-force | lbf | 0.004448 | 0.000454 | US customary |
How to work it out
- Separate force from mass first. kN is force; kg and t are mass, related through g = 9.80665 m/s², so one tonne of mass produces 9.80665 kN of weight.
- Basic relations: 1 kN = 1000 N, 1 MN = 1000 kN, 1 daN = 10 N (daN is common in European documentation).
- Gravitational units: 1 kgf = 9.80665 N and 1 tf = 9.80665 kN. Old drawings use tonnes-force, numerically close to metric tonnes but conceptually different.
- Anglo-American: 1 lbf = 4.44822 N and 1 kip = 1000 lbf = 4.44822 kN. US structural drawings use kip and kip/ft for loads.
- Field approximation: 1 t ≈ 10 kN, within 2%. Lifting, scaffolding and falsework estimates all use it — accurate enough and easy to remember.
- Check: 100 kN is about 10.2 tf or 22.5 kip. A wrong order means the wrong force unit.
Where it goes wrong
- Equating kN with kg. Ten kilonewtons is not 10 kg; it is the weight of about 1.02 t, a hundredfold difference. A crane rated 10 t is roughly 98 kN.
- Mixing kgf and N. One kgf is 9.8 N, not 1 N. The old 300 kg per square centimetre is 300 kgf/cm², or 2940 N/cm².
- Mixing kip and kN. One kip is 4.448 kN, so 100 kip on a US drawing is 445 kN, and reading it as 100 kN badly understates the load.
- Using the tonne as a force unit. Strictly the tonne is mass and the tonne-force is force. Colloquial use is fine, but calculations must state which.
- Mixing force and moment units in load combinations. Moments are kN·m while shear and axial are kN; mislabelling them gets calculations rejected at review.
Material and cost
In lifting and propping a force unit error is a safety incident. Reading a 10 t (98 kN) crane limit as 10 kN invites a tenfold overload and a collapse, and the same applies to scaffold and falsework capacity checks.
On site
- Two field rules carry most of the load: 1 t is about 10 kN, and 1 kN is about 100 kg.
- Rigging is marked with WLL in either tonnes or kN — check which at goods-in. A 1 t shackle commonly carries a WLL of 2 t through a safety factor of 4-6.
- Keep units consistent in calculations: kN and kN/m for loads, N/mm² (MPa) for material strength, kN·m for moments. Mixed units are a frequent reason for rejected submissions.
- European equipment data often uses daN: 1 daN = 10 N, so divide by 100 for kN.
Basis
- GB/T 3100-3102 Quantities and units series
- GB 50009-2012 Load code for the design of building structures, terms and symbols
- GB 50017-2017 Standard for design of steel structures, design principles
FAQ
Why are loads in kN rather than kg?
The kilogram measures mass and the kilonewton measures force, and structures respond to force. The same one-tonne machine weighs 9.8 kN on Earth and 1.6 kN on the Moon. A code live load of 2.0 kN/m² is a force, about 204 kg/m² of mass — which is where the “200 kg per square metre” floor label comes from.
How do wire rope tonnages convert to kN?
Multiply by 9.80665. A rope rated 10 t has a breaking force near 98 kN; divide by the safety factor for working load — 6 for lifting, 14 for man-riding. Check whether the maker quotes breaking force or working load, because they differ sixfold and getting it wrong kills people.
How heavy is 1 kN really?
About 102 kg — one adult, or two bags of cement. On site, allow roughly 1 kN per 100 kg: a 6 m length of 25 mm bar is 23 kg or 0.23 kN, and a 1 m² plate 10 mm thick is 78.5 kg or 0.77 kN.
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Force Unit Converter. 2026-10-25. https://jianzhujisuan.com/en/unit-force
Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.