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Compare two tire sizes
Choose a reference, calculate, and read the differences in that order.
Reviewed Oct 28, 2026
Set Original and New
Enter the starting size under Original and the candidate under New. Calculate after checking the parsed dimensions. A fixed comparison page opens with a stable pair; the editable tool lets you change either member.
Read the result table
Each difference is New minus Original. Positive means the new numeric value is greater, while negative means it is smaller. That sign is descriptive. It is not a warning level or an approval. An identical-size comparison returns zero differences without a safety verdict.
Swap to change the reference
Swap exchanges the original and new inputs and recalculates the model. Absolute differences reverse sign. Percentages and theoretical speed rows are recomputed with the new original denominator, so their magnitudes need not match the previous values.
Choose a diagram view and alignment
Use Side profile or Cross section to inspect the nominal geometry. Center alignment shares a center; ground alignment shares a bottom baseline. Both tires use the same drawing scale. A small numerical difference will remain a small visual difference.
Keep or export the comparison
Save a named local project when you want to return to the inputs. Download a report or table for another task. The scope note stays with the report because nominal geometry cannot resolve vehicle fitment.