Tire size comparison
225/50R17 vs 225/55R17
225/55R17 is +3.4% taller than 225/50R17: 26.7 in vs 25.9 in (+0.89 in), and the same width. With 225/55R17 on a vehicle set up for 225/50R17, the speedometer shows 60 mph at an actual 62.1 mph. That is more than the ±3% difference many shops use as a rule of thumb, so check carefully before switching.
Set up for: going bigger (225/55R17 instead of 225/50R17) · Different situation?
Your current size
e.g. 265/70R17, 2657017 or 33x12.50R20
Where do I find my size?
It's on the tire sidewall, e.g. P265/70R17 115T, and on the tire placard sticker on the driver's door jamb (also in the owner's manual). The placard shows the size the vehicle came with; the sidewall shows what is fitted now. If they differ, use the placard as your starting point. Digits are enough here: 2657017 or 33125020.
Size you're considering
225/50R17 vs 225/55R17: full comparison
| 225/50R17 | 225/55R17 | Difference | |
|---|---|---|---|
| Overall diameter | 25.86 in | 26.74 in | +0.89 in (+3.4%) |
| Width | 8.86 in | 8.86 in | ±0.00 in (±0.0%) |
| Sidewall height | 4.43 in | 4.87 in | +0.44 in |
| Circumference | 81.2 in | 84.0 in | +2.8 in |
| Revs per mile (nominal) | 780 | 754 | −26 |
| Wheel diameter | 17 in | 17 in | ±0 in |
| Diameter in mm | 657 | 679 | +22 mm |
Speedometer difference
Your speedometer is calibrated for 225/50R17. Fitted with 225/55R17, the actual speed is the reading × 26.74 ÷ 25.86.
| Speedometer shows | Actual speed | Difference |
|---|---|---|
| 20 mph | 20.7 mph | +0.7 mph |
| 30 mph | 31.0 mph | +1.0 mph |
| 45 mph | 46.5 mph | +1.5 mph |
| 55 mph | 56.9 mph | +1.9 mph |
| 60 mph | 62.1 mph | +2.1 mph |
| 70 mph | 72.4 mph | +2.4 mph |
| 80 mph | 82.7 mph | +2.7 mph |
Real tires: published diameters
225/50R17: 25.6–26.2 in published by 7 makers; 225/55R17: 26.5–27.1 in published by 7 makers. Calculated figures assume a nominal tire; the exact difference between two specific tires depends on their models.
More about each size: 225/50R17 · 225/55R17
Related comparisons
FAQ
Which is bigger, 225/50R17 or 225/55R17?
225/55R17 is +3.4% taller than 225/50R17: 26.7 in vs 25.9 in (+0.89 in).
How much will my speedometer be off with 225/55R17 instead of 225/50R17?
The speedometer is calibrated for 225/50R17. With 225/55R17 it shows 60 mph when you are doing 62.1 mph, and 70 mph at 72.4 mph (+3.4%). Your speedometer also has its own factory tolerance.
Can I replace 225/50R17 with 225/55R17?
The diameter difference is +3.4%. Whether it fits depends on things this calculation can't see: wheel width and offset, clearance at full lock and over bumps, load index and speed rating, and your vehicle maker's approval. Check your door-jamb placard and owner's manual and ask a tire professional.