All Tire Calculators

Convert tire pressure between PSI and Kilopascals.

OEM tire sizes for Subaru models 2013–2026 from Subaru's specifications. Compare tire size difference with an AWD check and see owner-reported lifted sizes.

Convert kilopascals to PSI for tire pressure, boost/MAP sensor readings, and vacuum. Full conversion chart, vehicle-type pressure guide, and TPMS unit-change instructions.

Compare P-Metric tire dimensions side-by-side.

Compare two tire sizes side-by-side. Diameter, sidewall, speedometer error, revs/mile, and visual chart. P-metric & flotation.

Find the exact diameter difference between two tire sizes. Commonly cited guidelines, speedometer error %, AWD guidelines, and effective gear ratio.

Calculate speedo error from tire size changes.

Convert tire pressure units: PSI and kPa.

Convert between wheel offset and backspace.

See how tire size changes impact effective gear ratio.

Calculate engine RPM at speed based on tire size & gear ratios.

Analyze diameter differences for staggered tire setups.

Calculate scrub radius from wheel offset (ET), tire size and SAI, or the change from a wheel offset, spacer or tire swap.

Calculate total tire height from P-Metric specs.

Check if a tire width is suitable for a given rim width.

Find the aspect ratio for a target tire diameter.

Find maximum load per tire from a load index number, using the Bridgestone International Load Index table.

Find max speed capability from a tire's speed rating letter.

Explore tire options for different wheel sizes.

Assess if a tire is stretched or pinched on a rim.

Estimate a tire's effective radius under load.

Decode the DOT date code and compare tire age with what NHTSA, vehicle makers and tire makers say about replacement.

Convert tire load range to ply rating, with maximum pressures and loads from the Bridgestone truck tire data book for example sizes.

Compare a spare tire with your regular tire: calculated diameter difference, spare sizes from owner's manuals, and what manufacturers say about spare speed limits and four-wheel drive.

Understand Treadwear, Traction and Temperature grades from NHTSA 49 CFR 575.104, with the traction coefficients and test procedures.

Estimate inner/outer clearance changes for new setups.

Estimate tire contact patch area from load and pressure.

Calculate tire sidewall height from P-Metric specs.

Calculate tire revolutions per mile and kilometer.

Estimate the internal air volume of a tire.

Calculate total tire diameter from P-Metric specs.

Understand camber and its effects on wear and handling.

Understand caster and its influence on steering stability.

Learn how toe-in/toe-out affects tire wear and stability.

Understand what a tire's UTQG treadwear rating signifies.

Understand a tire's UTQG temperature grade (A, B, or C).

Estimate remaining tread depth and prorated value of a tire.

Convert flotation tire sizes (35×12.50R17, etc.) to P-Metric and get full dimensions: diameter, sidewall, circumference, revs/mile.

Find the recommended rim width range for any tire section width using ETRTO guidelines.

Calculate sidewall height, overall diameter, and circumference for motorcycle tires.

Convert between P-Metric, flotation, and LT tire size formats with full dimension output.

Toyota tire size calculator for Camry, Corolla, RAV4, 4Runner and Tundra. Factory sizes from Toyota owner's manuals, diameter difference and speedometer error for any new size.

Calculate BMW tire fitment for any model: compare OEM vs aftermarket sizes, check the xDrive 1% rolling-diameter guideline, M-series staggered specs, and speedometer error.

Check if a BMW xDrive staggered tire setup is safe: compare front vs rear rolling diameter against the commonly cited 1% xDrive guideline and BMW factory pairs, with revs/mile and tread-depth wear check.

Convert metric tire sizes to inches, build P-metric/LT sizes, decode alpha-numeric vintage sizes, and look up load index in one free tool.

RAM 1500, 2500 and 3500 tire size calculator with tire sizes from RAM owner's manuals, diameter difference and speedometer error for any other size.

Mazda3, CX-5 & CX-30 tire size calculator: compare OEM vs plus-size options, check diameter difference and speedometer error instantly.

Decode any Mercedes tire size, compare two sizes with a 4MATIC rolling-diameter check, see factory sizes from Mercedes-Benz USA, and understand MO, MOE, MO1 and MOS tire markings.

Free Audi tire size calculator with factory sizes from Audi USA owner's manuals for A3, A4, A5, A6, RS 6, Q3, Q5, Q7, Q8, R8, Q4 e-tron, Q6 e-tron, Q8 e-tron and e-tron GT. Compare sizes, see the quattro AWD diameter check, speedometer error at 100/130 km/h, ground clearance change and load index check.

Find Tesla-approved tire sizes for Model 3, Y, S, X and Cybertruck from the Tesla Service Manual. Compare sizes, check the speedometer error, and see wheel nut torque. Free tool.

Calculate ATV flotation tire diameter, circumference, revs/mile, speedometer error, and ground clearance vs stock.

Mazda MX-5 Miata tire size calculator with NB, NC and ND factory sizes from Mazda owner's manuals. Decode sizes, compare stock vs new with speedometer correction, and find sizes by diameter.

Toyota Tacoma tire size calculator for all generations. Factory sizes from Toyota owner's manuals, stock vs new comparison with speedometer correction, sizes by diameter, and what Toyota says about lifts and larger tires.

Lexus tire size calculator for IS, ES, UX, NX, RX, RC, LC, GX and LX. Factory sizes from Lexus owner's manuals, stock vs new comparison with speedometer correction, and sizes by diameter.

Ford F-150 tire size calculator with tire sizes by trim from Ford specifications and owner's manuals, plus diameter change and speedometer correction for any other size.

Calculate total tire height (overall diameter) in inches or mm, from P-metric code, inches direct, or compare two sizes side-by-side. Five modes: metric decode, inches direct, comparison, wheel+tire total, and find by height.

Jeep tire size calculator for the Wrangler, Gladiator, Cherokee and Grand Cherokee. Sizes from Jeep owner's manuals, metric to inch conversion, speedometer correction and effective gear ratio.

Tractor tire size calculator to compare and convert ag tire sizes: diameter, circumference, rim fit, wheel speed error, MFWD lead and minimum pressure.

Tractor ballast calculator for 2WD, MFWA and 4WD tractors. Target axle weights from PTO power and speed, minimum tire pressure, and liquid ballast gallons.

Convert metric ↔ inch ↔ alpha sizes, look up OEM fitment, compare tires, get terrain pressure recommendations, and check rim compatibility for dirt bikes.

Decode any press-on, pneumatic, or metric forklift tire size. Get full inches & mm dimensions, metric ↔ imperial equivalents, wear thresholds, load index lookup, and brand fitment data for Toyota, Hyster, Yale, Clark, and more.

Calculate golf cart tire dimensions from any size (18×8.5-8, 20×10-10, etc).

Convert any rim size to bead seat diameter in millimeters, with automotive and bicycle (ETRTO) bead seat diameter charts.

Free truck tire size calculator covering all formats: metric (295/75R22.5), numeric (11R22.5), and flotation (35×12.50R17). Compare sizes, calculate effective gear ratio, speedometer correction, load/ply capacity, and view OEM semi truck tire charts and truck tire sizes from owner's manuals.

Calculate tire rolling resistance force (N), power loss (W/kW), and EV range impact for cars, SUVs, and trucks. Crr presets, 7 road surfaces, ISO 28580 dynamic Crr, grade, and aero drag.

GMC tire size calculator with tire sizes from GMC owner's manuals for the Sierra 1500, Sierra HD and Acadia, plus size comparison, speedometer correction and effective gear ratio.