SidewallerTire & wheel calculators

235/55R20 vs 255/55R20

255/55R20 is 2.9% taller (+0.87 in) and 0.79 in wider than 235/55R20.

OK
Close match

255/55R20 is 2.9% taller than 235/55R20. That is inside the ±3% most shops treat as a straight swap.

235/55R20255/55R20Change
Diameter30.18″31.04″+0.87″+2.9%
Width9.25″10.04″+0.79″+8.5%
Sidewall5.09″5.52″+0.43″+8.5%
Circumference94.8″97.5″+2.7″+2.9%
Wheel20″20″Same
Revs per mile668650−19
SideTread
235/55R20255/55R20
Speedometer shows 60 mph61.7mph

Real speed on 255/55R20.

Ground clearance+0.43in

Change in height under the axle.

Width per side+0.39in

On the same wheel, split inboard and outboard.

Shop 255/55R20 tires

Opens the store’s own search

Prices and stock change often, so check a few stores. We don’t earn anything from these links.

235/55R20 or 255/55R20?

Can I use 255/55R20 instead of 235/55R20?

255/55R20 is 2.9% taller than 235/55R20. That is inside the ±3% most shops treat as a straight swap. Also match or beat the original load index and speed rating, and check that the wheel width suits the new tire.

Will my speedometer be off?

At an indicated 60 mph on 255/55R20 you are really doing 61.7 mph if the speedometer was set up for 235/55R20. Going the other way, 235/55R20 would make it read 58.3 mph at a real 60.

How much ground clearance does it change?

Half the diameter difference: +0.43 in (+11 mm) under the axle.

Other comparisons