Converting holding force: kg, Newton and lbs
Short answer: 1 kg of holding force = 9.81 Newton (N) = 2.2 lbs (pounds). Rule of thumb: 10 N is roughly 1 kg, and 1 lb is roughly 0.45 kg. American and Asian sites often list higher numbers for the same magnet, because they use lbs or measure the holding force between two steel plates instead of on one plate. Always compare in the same unit and the same measuring method.
Conversion table
| kg | Newton (N) | lbs |
|---|---|---|
| 0.5 kg | 4.9 N | 1.1 lbs |
| 1 kg | 9.8 N | 2.2 lbs |
| 2 kg | 19.6 N | 4.4 lbs |
| 5 kg | 49 N | 11 lbs |
| 10 kg | 98 N | 22 lbs |
| 20 kg | 196 N | 44 lbs |
| 50 kg | 490 N | 110 lbs |
| 100 kg | 981 N | 220 lbs |
Formulas: N = kg × 9.81 | lbs = kg × 2.205 | kg = lbs × 0.4536 | kg = N ÷ 9.81.
Why do some sites state higher values?
- Unit: "10 lbs" sounds stronger than "4.5 kg", but it is the same.
- Measuring method: some suppliers measure the magnet between two steel plates. That gives a higher value, often 1.5 to 2 times, than the usual measurement on one thick plate. We state the holding force on one plate, perpendicular, as explained in how is holding force determined?
- Rounding and optimism: cheap suppliers sometimes quote theoretical or rounded values. So also compare size and grade: a Ø10 x 3 mm N48 holds approx. 1.6 kg, whatever the packaging says. See how strong is a neodymium magnet?
Kg, kgf and Newton: what is the difference?
Strictly speaking, kilogram is a mass and Newton is a force. When we say a magnet "holds 5 kg", we mean 5 kilogram-force (kgf): the force with which 5 kg is pulled by the earth, about 49 N. In the magnet world, kg and kgf are used interchangeably.
Frequently asked questions
How many Newton does a 1 kg magnet hold?
About 9.8 N.
Is holding force in kg the same as what I can hang from it?
No. Use a safety factor. See how many magnets do I need? and holding force, pull force and working load.
