Read the profile before comparing heights
Use both end heights and the footprint to judge the fit.
Start with the surface
Measure the clear width and length of the surface where the cushion will sit. Allow space around the edges and account for the size of both pieces when a set has separate supports.
Compare rise across the same span
A 14-inch maximum and a 7-inch low end represent a seven-inch change in height. A shorter ramp with the same rise can feel steeper. Compare the actual run where the ramp rises, rather than the full length if it includes a flat section.
Check how it settles
Published heights are usually unloaded unless the maker says otherwise. Foam can compress and an air chamber can shift shape. Try the support on a stable surface and stop if it shifts or feels uncomfortable.