Who We Are

TireSizeCalculator.site was founded by automotive enthusiasts and software engineers frustrated with cluttered, outdated, and inaccurate tire calculators online. Most web tools rely on oversimplified math that ignores essential fitment factors—such as wheel offset, backspacing, rim width stretching, drivetrain differential sync, and cold tire inflation load indexes.

We built a high-precision, client-side calculation suite designed specifically for car owners, truck builders, 4x4 off-roaders, track enthusiasts, and professional tire technicians.

Our Core Engineering Standards

Unlike calculators that approximate tire dimensions, all our formulas are strictly grounded in global automotive engineering specifications:

ISO 4000-1 Standards

International standard regulating metric passenger car tires and rims, defining theoretical cross-section width, aspect ratios, and design overall diameters.

TRA & ETRTO Guidelines

Tire and Rim Association (USA) and European Tyre and Rim Technical Organisation load/inflation tables for safe rim width matching and load index conversions.

Drivetrain Dynamics

Axle gear ratio calculations for ring and pinion re-gearing, revolutions-per-mile calibration, and AWD transfer case rotational tolerance synchronization (<1.0%).

Wheel Offset & Backspacing

Exact millimetric conversion between wheel centerlines, positive/negative offsets (ET), and SAE backspacing in inches to inspect suspension clearance.

Our 10 Specialized Fitment Tools

To provide complete wheel-well coverage, our platform includes 10 dedicated calculators:

✓ Tire Size Comparison & 2D Visualizer
✓ Wheel Offset & Backspacing Lab
✓ Axle Gear Ratio & Re-Gearing Tool
✓ Speedometer Drift & Ticket Risk Meter
✓ Plus-Sizing (+1, +2, +3) Calculator
✓ Flotation (Inches) to Metric Converter
✓ Tire Pressure & Load (PSI) Adjuster
✓ Staggered AWD Sync Tolerance Tool
✓ Tire to Wheel Rim Width Matcher
✓ Single Tire Height & Dimension Inspector

Editorial Independence & Accuracy

TireSizeCalculator.site is an independent publication. We do not sell tires, wheels, or hardware directly, which means our fitment recommendations, warnings (such as the automotive 3% diameter safety threshold), and technical evaluations remain unbiased and safety-first.

Have questions, feedback, or would like to suggest a new vehicle preset? Reach out directly via our Contact Page.