# Tire Size Calculator

> Calculate exact tire dimensions from standard sidewall codes.

Page: https://askcalculators.com/calculator/tire-size-calculator/
Definition: https://askcalculators.com/calculator/tire-size-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/tire-size-calculator/schema.json
Version: 7.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/tire-size-calculator/?width=225&ratio=45&diameter=17

## Inputs
- width: Width (mm); type=number; optional; default=225
- ratio: Aspect Ratio; type=number; optional; default=45
- diameter: Diameter (in); type=number; optional; default=17

## Outputs
- result: Result; format=text; primary

## Formula
Sidewall = width × aspect ratio; overall diameter = wheel diameter + 2×sidewall; circumference = π×diameter; speed difference follows circumference ratio.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.