Tire Size Comparison

Compare any two tire sizes side by side: overall diameter, section width, sidewall height and revs per mile, each one drawn to scale. Search a pair below, or browse the full directory of 304 comparisons.

Popular Comparisons:

265/70R17 vs 285/75R16 265/70R17 vs 285/70R17 275/70R18 vs 285/70R17 205/55R16 vs 215/60R16

Trending Tire Comparisons

8 Verified Presets

Truck / 4x4Exceeds ±3%

265/70R17vs285/75R16

Changes wheel diameter from 17" to 16", so this swap needs different wheels. Overall diameter moves +1.22" (+3.86%).

Truck / 4x4Exceeds ±3%

285/70R17vs265/75R16

Changes wheel diameter from 17" to 16", so this swap needs different wheels. Overall diameter moves -1.06" (-3.24%).

Off-RoadExceeds ±3%

265/70R17vs285/70R17

Keeps the same 17" wheel. Overall diameter changes +1.10", which is about 0.55" more ground clearance, and the speedometer reads 58 mph at a true 60.

Heavy DutyWithin ±3%

275/70R18vs285/70R17

Changes wheel diameter from 18" to 17", so this swap needs different wheels. Overall diameter moves -0.45" (-1.36%).

SUV / CrossoverExceeds ±3%

235/70R16vs245/75R16

Keeps the same 16" wheel. Overall diameter changes +1.52", which is about 0.76" more ground clearance, and the speedometer reads 57 mph at a true 60.

SUV / CrossoverWithin ±3%

235/65R17vs255/60R17

Keeps the same 17" wheel. Overall diameter changes +0.02", which is about 0.01" more ground clearance, and the speedometer reads 60 mph at a true 60.

Passenger / SedanExceeds ±3%

205/55R16vs215/60R16

Keeps the same 16" wheel. Overall diameter changes +1.28", which is about 0.64" more ground clearance, and the speedometer reads 57.1 mph at a true 60.

Plus-One WheelWithin ±3%

225/45R17vs225/40R18

Changes wheel diameter from 17" to 18", so this swap needs different wheels. Overall diameter moves +0.12" (+0.48%).

What Changes When You Change Tire Size

Four numbers decide whether a swap works. Every comparison page reports all of them for the specific pair, alongside a diagram drawn to scale.

Overall diameter

The one that matters most. Diameter sets ride height and ground clearance, and half of any diameter change goes to clearance because the axle sits at the centre. It also drives everything below.

Speedometer error

A larger tire covers more ground per turn, so the speedometer under-reads. This is why the 3 percent rule exists: past roughly 3 percent the error gets large enough to matter, and on many vehicles the ABS and traction systems read wheel speed too.

Section width and sidewall

Width is the tire at its widest point, not the tread. Sidewall height is the aspect ratio applied to that width, so the same 65 series is a taller sidewall on a wider tire. Width decides whether the tire clears the strut and the fender.

Revs per mile

How many times the tire turns in a mile, which sets effective gearing. We publish the loaded figure, corrected by a factor measured against manufacturer data books, because a loaded tire flattens at the contact patch and turns about 3 percent more than the bare geometry predicts.

All Tire Size Comparisons

304 comparisons

Truck, 4x4 and Off-Road

Wide, tall sizes where a swap usually means new wheels as well as new tires. Diameter changes here move ground clearance and gearing the most.

SUV and Crossover

Mid-width sizes on 16 to 18 inch wheels. Most swaps in this group stay inside 3 percent, so the speedometer error stays small.

Passenger Car and Sedan

Narrower sizes where sidewall height, not width, does most of the work. Small diameter changes show up quickly as speedometer error.