Calwarden
Back to calculator
EV & CarsGenerated accuracy model review: 2026-05-06

Wheel Offset Calculator accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

  • Backspacing = half wheel width + offset. Outer poke change = new frontspace - old frontspace.

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

  • Original Wheel Width: 8 in
  • Original Offset: 45 mm
  • New Wheel Width: 9 in
  • New Offset: 35 mm

Expected outputs

  • Outer Poke Change: 22.7 mm
  • Inner Clearance Change: -2.7 mm
  • Original Backspacing: 146.6 mm
  • New Backspacing: 149.3 mm

Known limitations

  • This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
  • Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

  • All prices, fees, rates, and vehicle assumptions are user-entered.
  • Calculations run locally in your browser and are not stored by Calwarden.
  • This is planning math, not financial, tax, insurance, legal, or mechanical advice.

Unit handling

  • Original Wheel Width accepts values in in.
  • Original Offset accepts values in mm.
  • New Wheel Width accepts values in in.
  • New Offset accepts values in mm.
  • Outer Poke Change is displayed in mm.
  • Inner Clearance Change is displayed in mm.
  • Original Backspacing is displayed in mm.
  • New Backspacing is displayed in mm.

Rounding rules

  • Number displays use up to 2 decimal places in the calculator UI.
  • Input precision follows configured step values where provided.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current wheel-offset-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Wheel Offset Calculator.

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

Use calculator