Tire Calculator (Offset&Speed)

Easily calculate the effects of wheel and tire size changes

A convenient calculation tool for anyone considering wheel upgrades, tire size changes, or fitment adjustments.

Simply enter your current and new specifications to quickly compare the impact on your vehicle.

-Main Features

-Wheel Comparison

•Calculate inner rim position changes

•Calculate outer rim position changes

•Calculate tread width changes

-Tire Comparison

•Calculate speedometer error (%)

•Compare indicated speed and actual speed

•Vehicle-specific speedometer error can also be included in calculations

-Speedometer Error Measurement

•Accurate GPS-based speed measurement

-Data Storage

•Save comparison records

-Important Notes

Measurement results may vary depending on GPS reception and environmental conditions. Use measured values as a reference only.

Actual wheel and tire dimensions may vary by manufacturer and model. Calculation results are for reference purposes only.

Always consult a qualified professional before making vehicle modifications.

The developer assumes no responsibility for any damages or issues resulting from the use of this application.

-Specifications

Wheel Offset Calculator

•Rim Width (in): 3" to 16" (supports 0.25" increments)

•Offset (mm): -60 to +70

•Backspacing (in): 3" to 13"

Speedometer Error Calculator

•Tire Width (mm): 125 to 405

•Aspect Ratio (%): 20 to 90, including 82 (R)

•Supports 82-series radial tires commonly used on vans and light trucks

•Rim Diameter (in): 10 to 32

•Direct Tire Diameter Input: 100 to 1500 mm or 4 to 60 in

•Vehicle Speedometer Error Correction (%): -20 to +20

Speedometer Error Measurement

•Measurable speed range: 10 to 200 km/h or 10 to 200 mph