How to measure spring rate?

[KiDX]

I recently purchased a 2000 KX 250 from a guy who was 200+ lbs and had the suspension redone. Being only 150 lbs. it was way too stiff for me. I replaced the stiff shock spring with the stock one, and I was wondering if there is any way to tell what the spring rate is. I was hoping to find it stamped on there but it wasn't. :(

 

[DENNY]

If you can't find spring tention gauge try this. Find a H-frame press and a bathroom scales. Put the spring on top of the scales and place both of them into the H-frame. Compress the spring 1 inch and read the scales Then compress one more inch and read the scales. If the weight doubles the spring is not a progressive rate and the rate is the first reading.