Measuring real tire dimensions
Choosing and Buying a Tire Tread Depth Gauge: Start With the Sidewall Numbers
How to read tire sidewall markings, calculate tire size, convert 32nds of an inch to millimeters, and choose a digital or analog tread depth gauge from Walmart, AutoZone, Harbor Freight or Amazon.
How Heat Affects Tire Dimensions: From Sidewall Numbers to Hot vs Cold Diameter
How heat affects tire dimensions: what the sidewall size numbers mean, how to calculate diameter and circumference, and why hot and cold tire measurements differ.
How to Measure Wheel Diameter: From Sidewall Numbers to Tape Measure
Find rim diameter on a car or bike tire sidewall, calculate overall wheel diameter and circumference, and measure a wheel with a tape measure.
Out-of-Round Tire Warranty Claims: From Sidewall Numbers to a Documented Claim
How to read the tire sidewall, what radial runout means, how out-of-round tires are inspected and documented, and how warranty terms usually treat roundness claims.
Tire Tread Void Ratio: Meaning and Calculation
What tire tread void ratio means, how to calculate it from groove and tread area, and how it relates to sidewall markings, tire size calculations and fitment limits.
Tire Tread Pitch: What It Means and How It Relates to the Numbers on the Sidewall
What tire tread pitch means, how pitch length and variable pitch sequences work, and how sidewall size numbers set the circumference that the tread pitches divide.
Motorcycle Tire Contact Patch Size Explained
How to read motorcycle tire sidewall markings, calculate sidewall height, diameter and circumference, and understand what really sets motorcycle tire contact patch size.
Tire Shoulder Shape: Rounded and Square Profiles Explained, Starting With the Sidewall Numbers
How to read tire sidewall numbers, how width, aspect ratio and rim diameter shape the cross-sectional profile, and how rounded and square tire shoulders differ.
How to Measure and Calculate Tire Circumference
Calculate tire circumference from sidewall numbers, measure it on a mounted tire with a tape or rollout, and see why calculated, measured, and rolling values differ.
Tire Diameter Growth at Speed: From Sidewall Numbers to Drag Tire Expansion
How tire diameter grows at speed, starting with sidewall size markings. Calculate diameter and circumference, see why bias drag slicks grow more than radials, and estimate growth from trap speed and rpm.