Convert Kip to Femtonewtons
Convert Kip (kip) to Femtonewtons (fN) instantly and accurately.
Conversion Formula
fN = kip × 4.448221615e+18
About Kip
One kip (kilo-pound) is exactly 1,000 lbf - approximately 4,448 N. It is the primary force unit in US structural engineering: AISC and ACI 318 specify column loads, beam reactions, and connection capacities in kips and kip·ft or kip·in. 'ksi' (kips per square inch) gives steel yield strength - ASTM A36 yields at 36 ksi; A992/A572 at 50 ksi. Crane capacities, prestressed concrete jacking forces, and soil bearing limits in US geotechnical practice are all in kips. 1 kip = 1,000 lbf = 4,448.22 N = 453.59 kgf.
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
| Kip (kip) | Femtonewtons (fN) |
|---|---|
| 1 kip | 4.448 × 1018 fN |
| 2 kip | 8.896 × 1018 fN |
| 5 kip | 2.224 × 1019 fN |
| 10 kip | 4.448 × 1019 fN |
| 25 kip | 1.112 × 1020 fN |
| 50 kip | 2.224 × 1020 fN |
| 100 kip | 4.448 × 1020 fN |