Spring Calculator
Find the rate of a helical compression spring.
A helical spring's stiffness depends strongly on its wire and coil diameters.
The math behind it
k = G·d⁴ ÷ (8·D³·n). Thicker wire stiffens dramatically (d⁴); larger coils soften it (D³).
Worked example
Steel, 2 mm wire, 20 mm coil, 8 coils → about 0.99 N/mm.
FAQ
How to make a stiffer spring?
Use thicker wire, a smaller coil diameter or fewer active coils.