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Same 20 in wheel · side by side

285/55R20 vs 305/55R20

First size

mm, 115–395
% of width
inches

Second size

mm, 115–395
% of width
inches

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

Difference in overall diameter

+2.68%

305/55R20 is 0.87 in taller than 285/55R20 (+2.68%) and 0.79 in wider; at an indicated 60 mph you are doing 61.6 mph.

285/55R20 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 285/55R20 at 32.34 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 0.87 in.0.87 inDETAIL — ENLARGED285/55R20 · 32.34 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

285/55R20 and 305/55R20, one measurement per row; the difference is 305/55R20 minus 285/55R20
Measure­ment 285/55R20 305/55R20 Differ­ence
Overall diameter32.34 in33.21 in+0.87 in · +2.68%
Section width11.22 in12.01 in+0.79 in
Sidewall height6.17 in6.60 in+0.43 in
Circumference101.61 in104.33 in+2.72 in
Revolutions per mile623.6607.3−16.3

Other pairs with one of these two in them

Each size on its own