What is the diameter difference between 225/45R17 and 245/35R19?

225/45R17 has an overall diameter of 24.97 inches (634 mm). 245/35R19 is 25.75 inches (654 mm). That's a 0.78 inch (20 mm) difference — 245/35R19 is taller.

Will 245/35R19 cause speedometer error on a car fitted with 225/45R17?

Swapping 225/45R17 for 245/35R19 produces a speedometer error of about 3.1%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 61.9 mph. Anything under 3% is usually acceptable without recalibration.

How many revolutions per mile does each size do?

225/45R17 turns 808 revs per mile. 245/35R19 turns 783 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.

What's the sidewall height difference?

225/45R17 has a sidewall of 101 mm (3.99 in). 245/35R19 sidewall is 86 mm (3.38 in). Lower-profile sidewalls give sharper steering response but less bump compliance.

Is 245/35R19 a safe plus-size upgrade from 225/45R17?

A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 3.1%. This swap is outside the typical ±3% safe range and may require speedometer recalibration or affect ABS / traction control behaviour.

Tire size comparison

225/45R17 vs 245/35R19

Overall diameter, sidewall, revs per mile, and speedometer error — 245/35R19 is the taller tire, with a 3.1% speedo delta when swapping.

225/45R17

24.97in

634 mm overall diameter

245/35R19

25.75in

654 mm overall diameter

Diameter Δ

0.78 in

Speedo error

3.1%

225/45R17 revs/mi

808

245/35R19 revs/mi

783

Outside the typical ±3% safe plus-size band — you may want speedometer recalibration, and this change can affect ABS or traction control behaviour.

Full spec

Side by side

Metric	225/45R17	245/35R19
Section width	225 mm	245 mm
Aspect ratio	45	35
Wheel diameter	17″	19″
Sidewall height	101 mm	86 mm
Overall diameter	24.97 in (634 mm)	25.75 in (654 mm)
Circumference	78.45 in	80.9 in
Revolutions / mile	808	783

Other comparisons for these sizes

215/50R17 vs 225/45R17 225/50R17 vs 225/45R17 225/45R17 vs 235/40R18 225/45R17 vs 225/40R18 225/45R17 vs 235/45R17 225/45R17 vs 245/45R17 235/40R18 vs 245/35R19 245/40R18 vs 245/35R19 225/35R19 vs 245/35R19 235/35R19 vs 245/35R19

FAQ

Frequently asked

What is the diameter difference between 225/45R17 and 245/35R19?: 225/45R17 has an overall diameter of 24.97 inches (634 mm). 245/35R19 is 25.75 inches (654 mm). That's a 0.78 inch (20 mm) difference — 245/35R19 is taller.
Will 245/35R19 cause speedometer error on a car fitted with 225/45R17?: Swapping 225/45R17 for 245/35R19 produces a speedometer error of about 3.1%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 61.9 mph. Anything under 3% is usually acceptable without recalibration.
How many revolutions per mile does each size do?: 225/45R17 turns 808 revs per mile. 245/35R19 turns 783 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.
What's the sidewall height difference?: 225/45R17 has a sidewall of 101 mm (3.99 in). 245/35R19 sidewall is 86 mm (3.38 in). Lower-profile sidewalls give sharper steering response but less bump compliance.
Is 245/35R19 a safe plus-size upgrade from 225/45R17?: A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 3.1%. This swap is outside the typical ±3% safe range and may require speedometer recalibration or affect ABS / traction control behaviour.