CarSpecsHQ

245/35R20 vs 225/45R19

225/45R19 is a safe swap for 245/35R20 by the usual ±3% rule: the diameter differs by +0.82%.

20" → 19"
245/35R20 26.75" · 225/45R19 26.97" · drawn to scale

Side by side

245/35R20225/45R19Difference
Overall diameter26.75"26.97"+0.22" (+0.82%)
Section width245 mm225 mm-20 mm
Sidewall3.38"3.99"+0.61"
Rim20"19"-1"
Circumference84.0"84.7"+0.7"
Revs per mile754748-6
Ride height——+0.11"
Speedometer reads 60 mph60.060.5+0.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.5 mph

With 225/45R19 on a car calibrated for 245/35R20, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.8%.

Speedo showsActual speed
30 mph30.2 mph
45 mph45.4 mph
60 mph60.5 mph
70 mph70.6 mph
80 mph80.7 mph

Other sizes close to 245/35R20

Questions

Can I replace 245/35R20 with 225/45R19?

225/45R19 is a safe swap for 245/35R20 by the usual ±3% rule: the diameter differs by +0.82%.

What's the difference between 245/35R20 and 225/45R19?

225/45R19 is 0.22" taller and 20 mm narrower; the sidewall is +0.61". At an indicated 60 mph you'd actually be doing 60.5 mph.

Will 225/45R19 fit on 245/35R20 wheels?

No — 245/35R20 needs a 20" wheel and 225/45R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.