TyreFit Geometry

KATHERINE MOTORS LTD

About this app

TyreFit Geometry is a dedicated wheel and tyre fitment calculator designed to make automotive measurements easier to understand.

Compare tyre sizes, wheel dimensions and offsets in one focused workspace. Explore geometric changes between a current setup and a proposed setup, calculate key measurements, and view the results through clear technical visualizations.

Tyre Size Calculator

Enter a tyre specification such as 225/45 R17 and calculate:

• Tyre width
• Sidewall height
• Overall diameter
• Radius
• Circumference
• Diameter difference
• Circumference difference
• Percentage change

TyreFit Geometry helps turn familiar tyre markings into useful measurements that are easier to compare.

Wheel Offset Calculator

Analyze wheel offset and width changes between two configurations.

Compare:

• Wheel width
• Offset
• Inner movement
• Outer movement
• Centerline changes
• Wheel position differences

The geometric comparison makes it easier to understand how changing wheel specifications can alter the calculated position of a wheel.

Visual Fitment Comparison

See current and proposed tyre dimensions together with measurement diagrams.

The visual comparison is designed to make numerical differences easier to interpret instead of presenting calculations as a simple list of numbers.

Fitment Delta

Quickly review the calculated change between two setups.

View differences for:

• Diameter
• Width
• Outer position
• Inner position
• Circumference
• Speedometer-related calculations

Guessing from isolated numbers

Compare the geometry.

Speedometer Analysis

Calculate the estimated speed difference resulting from a change in tyre diameter.

Enter a displayed speed and compare it with the calculated value based on the selected tyre dimensions.

Support for km/h and mph makes the tool suitable for different measurement preferences.

Quick Tyre Check

Need a fast calculation?

Enter a standard tyre format and get the essential dimensions without building a complete comparison.

TyreFit Geometry supports common formats such as:

225/45 R17
245/40 R18
255/35 R19

Input validation helps identify incomplete or incorrectly formatted specifications.

Wheel Measurement Tools

Use dedicated tools for common automotive measurements and conversions, including:

• Wheel diameter
• Wheel width
• Offset
• Spacer thickness
• Millimeter and inch conversions

Everything is organized around automotive wheel and tyre geometry rather than a generic unit-converter interface.

Save Your Setups

Keep useful comparisons available in the app with local saved setups.

Create labels such as:

Daily Setup
Winter Setup
18-inch Upgrade
Track Setup

Saved comparisons can be renamed, duplicated, favorited, or deleted.

Designed for Automotive Calculations

TyreFit Geometry is built for people who want a clearer way to work with wheel and tyre measurements, including vehicle owners, automotive enthusiasts, mechanics, wheel specialists, and students.

A collection of unrelated calculators

One focused workspace for tyre and wheel geometry.

Privacy-Focused Local Design

TyreFit Geometry is designed to perform its calculations locally on your device.

Your tyre and wheel calculations do not need an online account or cloud synchronization. The app is designed around local use, with saved setups kept on the device.

Important Fitment Note

TyreFit Geometry provides mathematical calculations and geometric comparisons for reference. Actual vehicle fitment can depend on factors such as suspension geometry, brake clearance, wheel design, tyre construction, manufacturer specifications, load requirements, and physical vehicle tolerances.

Always verify the actual installation requirements and physical clearance before fitting a different wheel or tyre configuration.

TyreFit Geometry
Wheel & Tyre Fitment Laboratory