Data & Calculation Standards

Metric sizes (for example 275/70R18 or LT265/75R16) are parsed into section width, aspect ratio, construction letter and wheel diameter. Flotation sizes (for example 33x12.50R17) are parsed into overall diameter, section width, construction and wheel diameter.

• Sidewall height = section width × (aspect ratio ÷ 100), converted to inches when displayed in imperial units.
• Overall diameter = wheel diameter + two sidewalls (metric path) or the stated flotation diameter.
• Circumference = π × overall diameter.
• Theoretical revolutions per mile = inches per mile ÷ circumference.

Rounding is applied for display so values stay readable. Underlying geometry uses full floating-point precision before formatting. These figures are nominal — not mounted measurements for a specific tire model.

Calculator logic last updated: July 2026.

Calculated values

• Overall diameter
• Section width
• Sidewall height
• Circumference
• Theoretical revolutions per mile
• Dimensional differences between sizes

Dataset-derived values

• Production-size status (common / limited coverage in our index)
• Tire categories
• Tire models offered in a size
• Brand availability
• Vehicle-type classifications
• Known vehicle examples where supported

Structured catalog data last checked: July 2026.

Model availability may change as manufacturers update product lines. A tire model is shown as available for a size only when our structured database contains an exact selected-size record. Absence from Tire Reference does not prove that a tire is unavailable elsewhere. Confirm availability and service specifications with the manufacturer or seller.

Tire Reference does not confirm vehicle fitment. Fitment can vary by model year, trim, wheel width, offset, load requirements, suspension configuration and available clearance.

You can submit:

• Calculation issues
• Incorrect product availability
• Broken links
• Outdated tire data
• Vehicle-classification corrections

Use the report an issue form or contact page. Include the tire size, page URL and a brief description when possible.

Visible update dates change only when:

• Calculation logic changes
• Relevant catalog data is reviewed
• Product records are updated
• Material explanatory content is revised

Dates are not auto-generated on every build. We do not publish a fixed manual-review cadence.

We are building a manufacturer-specification validation dataset that compares nominal calculated overall diameters with published manufacturer values. Results will be published only after sufficient records have been independently checked. No accuracy percentage is shown until then.