Metric Tire to Inches Converter

Enter a metric size such as 265/70R17 to see its theoretical inch dimensions.

Tire size

—Overall diameter

—Width

—Sidewall

—Wheel diameter

—Metric tire code converted to theoretical inch dimensions.

Automotive tolerance cluster

Calculate the nominal spec, then expose how real-world input spread can move it

Vehicle calculations are often exact only on paper. This cluster keeps the base result while making rolling radius, gearing, wheel measurements and performance-input sensitivity visible.

Tire size Gear ratio Speedometer

All 23 automotive tools

RPM ↔ SpeedRolling diameter + ratio spread → calibration envelope Engine DisplacementBore/stroke spread → swept-volume envelope Wheel BackspacingWidth/flange/input spread → backspacing envelope Wheel OffsetWidth/offset spread → inner/poke envelope Power-to-WeightPower/mass spread → ratio sensitivity Speed Per GearTire/gearing/redline spread → per-gear envelope Tire ComparisonReal rolling diameter → speedometer envelope Tire SidewallWidth/aspect spread → sidewall/diameter envelope

Metric tire geometry & speedometer comparison

Turn a metric size into sidewall height, overall diameter, circumference and revolutions per mile. Compare a second size to estimate speedometer error at a chosen indicated speed.

Width (mm)Aspect ratio (%)Wheel (in)Compare sizeIndicated speed

—Overall diameter

—Circumference

—Rev / mile

—Actual speed

Ready.

How the inch dimensions are derived

Metric tire notation combines section width in millimeters, aspect ratio and wheel diameter in inches. The converter calculates two sidewalls plus the wheel for theoretical overall diameter. It does not predict clearance, loaded radius or whether a tire is approved for a particular rim or vehicle.