Is "steepness" a proper word? [closed]

I am a marketing writer and am working on a product description, which would be as follows:

We track cool metrics like location, duration, speed and steepness.

Is that use of the word correct? Any insight would be wonderful.

Solution 1:

I humbly suggest degree of incline or just slope:

The grade (also called slope, incline, gradient, pitch or rise) of a physical feature, topographic landform or constructed element, refers to the amount of inclination of that surface to the horizontal.

Solution 2:

Grade is what they call it in civil engineering and by bicyclists.

Article about San Francisco hills and grades

Solution 3:

I don't really see why steepness shouldn't be treated as a valid word. It's basic sense is: how steep something is. It is not necessarily asking the degree of incline, or the type of slope. The primary sense is how much an object possesses the quality of being steep.

The OED also defines it as such:

The quality or condition of being steep.