Spring Rate Conversion: kg/mm to lb/in Chart & Calculator

This page covers spring rate conversion between kg/mm and lb/in - the two units used by coilover and lowering spring manufacturers. Use the calculator above for instant conversions, or refer to the reference table below for common coilover spring rates.

Many of our customers are looking to buy coilovers or lowering springs for their car. Half of the manufacturers show their spring rates as kg/mm while others show them as lbs/in. It's easy to forget what the conversion is so we put together a quick and easy chart to use for reference.

We also offer Swift Springs and Eibach replacement coilover springs so you can upgrade your spring rate or fine tune your ride quality with your existing aftermarket coilovers on your car or truck. These are available in various sizes and spring rates.

Roughly 1 KG/mm is equal to 55.997 LBS/in. Easy way to remember is 1 KG/mm = 56 LBS/in.

Common Coilover Spring Rate Reference

N/mm to lb/in Conversion

Some European manufacturers list spring rates in N/mm. The conversion is: 1 N/mm = 5.71 lb/in. To convert N/mm to kg/mm, divide by 9.807.

Shopping for coilovers or replacement springs? Browse our full selection including coilovers, Tein coilovers, and BC Racing coilovers.

Hope you guys find this helpful! Let us know if you have any questions about these numbers.