CarSpecsHQ

225/60R17 vs 245/50R18

245/50R18 is a safe swap for 225/60R17 by the usual ±3% rule: the diameter differs by +0.06%.

17" → 18"
225/60R17 27.63" · 245/50R18 27.65" · drawn to scale

Side by side

225/60R17245/50R18Difference
Overall diameter27.63"27.65"+0.02" (+0.06%)
Section width225 mm245 mm+20 mm
Sidewall5.31"4.82"-0.49"
Rim17"18"+1"
Circumference86.8"86.9"+0.0"
Revs per mile730730-0
Ride height——+0.01"
Speedometer reads 60 mph60.060.0+0.0 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.0 mph

With 245/50R18 on a car calibrated for 225/60R17, the speedometer reads 60.0 mph when you're really doing 60, and the odometer under-counts by 0.1%.

Speedo showsActual speed
30 mph30.0 mph
45 mph45.0 mph
60 mph60.0 mph
70 mph70.0 mph
80 mph80.0 mph

Other sizes close to 225/60R17

Questions

Can I replace 225/60R17 with 245/50R18?

245/50R18 is a safe swap for 225/60R17 by the usual ±3% rule: the diameter differs by +0.06%.

What's the difference between 225/60R17 and 245/50R18?

245/50R18 is 0.02" taller and 20 mm wider; the sidewall is -0.49". At an indicated 60 mph you'd actually be doing 60.0 mph.

Will 245/50R18 fit on 225/60R17 wheels?

No — 225/60R17 needs a 17" wheel and 245/50R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.