Convert Kilogram-Force to Femtonewtons
Convert Kilogram-Force (kgf) to Femtonewtons (fN) instantly and accurately.
Conversion Formula
fN = kgf × 9.806650000e+15
About Kilogram-Force
The kilogram-force (kgf), also called the kilopond (kp), is the gravitational force on 1 kg under standard gravity - exactly 9.80665 N. It was the primary force unit in continental European engineering before SI. ISO 1000 (1973) and EU Directive 80/181/EEC deprecated it in favour of the newton. Spring and bathroom scales reading in 'kg' technically measure kgf. Older DIN and JIS materials standards give tensile strength in kgf/mm² (× 9.80665 = MPa). Hydraulic cylinder ratings in legacy European machinery use kgf or tonne-force. 1 kgf = 9.80665 N = 2.20462 lbf.
About Femtonewtons
A femtonewton (fN) is 10⁻¹⁵ N - the force scale of single-molecule biology. RNA polymerase exerts a stall force of ~14-25 fN while transiting DNA at 10-50 bp/s. Myosin V motor proteins step 37 nm with ~1-3 fN per head. The viscous drag on a 100 nm nanoparticle moving at 1 µm/s through cytoplasm is ~0.2-0.5 fN. Optical tweezers with back-focal-plane detection resolve sub-femtonewton forces, enabling measurement of single-enzyme output. AFM receptor-ligand unbinding (e.g., biotin-streptavidin) gives adhesion forces of 100-300 fN. 1 fN = 10⁻¹⁵ N.
Quick Reference Table
| Kilogram-Force (kgf) | Femtonewtons (fN) |
|---|---|
| 1 kgf | 9.807 × 1015 fN |
| 2 kgf | 1.961 × 1016 fN |
| 5 kgf | 4.903 × 1016 fN |
| 10 kgf | 9.807 × 1016 fN |
| 25 kgf | 2.452 × 1017 fN |
| 50 kgf | 4.903 × 1017 fN |
| 100 kgf | 9.807 × 1017 fN |