How this calculator works
Rolling resistance represents dissipative effects such as tire deformation. Its dimensionless coefficient is force divided by normal load. Another convention uses a length b, related approximately to the ratio by b divided by loaded radius. This page keeps the two conventions separate. Mass mode assumes a level surface with normal load equal to weight. The 0.01 passenger-tire reference is a broad example, not a tire or road-specific prediction.
Formula
F_rr=C_rr N; N=mg on level ground; C_rr=b/r; b=F_rr r/N.
Worked example
A 1000 kg vehicle at g=10 m/s2 with C_rr=0.01 has rolling resistance 100 N. With b=0.003 m and r=0.3 m, C_rr is also 0.01.
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Frequently asked questions
Is this the tire grip coefficient?
No. Rolling resistance describes energy loss while rolling, while grip limits traction before sliding.
Why is one coefficient measured in length?
The length convention describes the moment arm of a resisting load. Dividing by wheel radius gives a force ratio.
Can I use mass on a slope?
Enter the actual normal load instead. The simple mass mode assumes a level surface.