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Same 20 in wheel · side by side

285/60R20 vs 305/55R20

First size

mm, 115–395
% of width
inches

Second size

mm, 115–395
% of width
inches

Comparing 285/60R20 · 305/55R20. Change any field and both follow.

Difference in overall diameter

−0.76%

305/55R20 is 0.26 in shorter than 285/60R20 (−0.76%) and 0.79 in wider; at an indicated 60 mph you are doing 59.5 mph.

285/60R20 and 305/55R20 laid over each other at one scale, with the gap enlargedTwo circles drawn at one scale and sharing a center: the solid ring is 285/60R20 at 33.46 in overall, the dashed ring is 305/55R20 at 33.21 in. A detail view beside them shows the same two edges enlarged, with the gap between them dimensioned at 0.26 in.0.26 inDETAIL — ENLARGED285/60R20 · 33.46 in305/55R20 · 33.21 in
Both overall diameters at one scale, sharing a center. The detail beside them enlarges the one place they differ, and its dimension is the difference the table below states.

The difference, one row at a time

285/60R20 and 305/55R20, one measurement per row; the difference is 305/55R20 minus 285/60R20
Measure­ment 285/60R20 305/55R20 Differ­ence
Overall diameter33.46 in33.21 in−0.26 in · −0.76%
Section width11.22 in12.01 in+0.79 in
Sidewall height6.73 in6.60 in−0.13 in
Circumference105.13 in104.33 in−0.80 in
Revolutions per mile602.7607.3+4.6

Other pairs with one of these two in them

Each size on its own