For reference only — not a substitute for professional engineering judgement. See Terms.

Enter any value — the others calculate automatically. Shaded fields are calculated; white fields are user-entered.

Radius

m
ft
chains
°/100 ft
Formula reference & definitions

Unit conversion:

1 ft = 0.3048 m    1 chain = 20.1168 m

Degree of curvature — 100 ft arc definition (railway standard):

D = 5729.578 / Rft   (°/100 ft)   ≡   1746.4 / Rm