# Tools

## Tire tools

- [Tire size calculator](/tools/tire-size-calculator): Compare two sizes and the speedometer error
- [Tire size decoder](/tools/tire-size-decoder): What every part of the sidewall code means
- [Tire sizes in inches](/tools/tire-size): 56 common sizes converted
- [Load index chart](/tools/tire-load-index-chart): Max load per tire, 70-126
- [Speed rating chart](/tools/tire-speed-rating-chart): L to Y in mph and km/h

## Look-ups

- [Trouble code lookup](/codes): What your OBD-II code means
- [Warning light finder](/warning-lights): Dashboard symbols by colour
- [Repair cost guide](/cost): 2026 prices for common repairs

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Source page: https://diagxcar.com/tools
General information, not a substitute for a qualified mechanic.