Tire size comparison
195/55R15 vs 205/50R15
205/50R15 is −1.6% shorter than 195/55R15: 23.1 in vs 23.4 in (−0.37 in), and 0.4 in wider. With 205/50R15 on a vehicle set up for 195/55R15, the speedometer shows 60 mph at an actual 59.0 mph. That is within the ±3% difference many shops use as a rule of thumb (not a manufacturer or legal limit).
Set up for: checking a replacement size (205/50R15 instead of 195/55R15) · 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
195/55R15 vs 205/50R15: full comparison
| 195/55R15 | 205/50R15 | Difference | |
|---|---|---|---|
| Overall diameter | 23.44 in | 23.07 in | −0.37 in (−1.6%) |
| Width | 7.68 in | 8.07 in | +0.39 in (+5.1%) |
| Sidewall height | 4.22 in | 4.04 in | −0.19 in |
| Circumference | 73.7 in | 72.5 in | −1.2 in |
| Revs per mile (nominal) | 860 | 874 | +14 |
| Wheel diameter | 15 in | 15 in | ±0 in |
| Diameter in mm | 595 | 586 | −10 mm |
Speedometer difference
Your speedometer is calibrated for 195/55R15. Fitted with 205/50R15, the actual speed is the reading × 23.07 ÷ 23.44.
| Speedometer shows | Actual speed | Difference |
|---|---|---|
| 20 mph | 19.7 mph | −0.3 mph |
| 30 mph | 29.5 mph | −0.5 mph |
| 45 mph | 44.3 mph | −0.7 mph |
| 55 mph | 54.1 mph | −0.9 mph |
| 60 mph | 59.0 mph | −1.0 mph |
| 70 mph | 68.9 mph | −1.1 mph |
| 80 mph | 78.7 mph | −1.3 mph |
Real tires: published diameters
195/55R15: 23.3–23.5 in published by 3 makers; 205/50R15: 22.95–23.11 in published by 5 makers. Calculated figures assume a nominal tire; the exact difference between two specific tires depends on their models.
More about each size: 195/55R15 · 205/50R15
Related comparisons
FAQ
Which is bigger, 195/55R15 or 205/50R15?
205/50R15 is −1.6% shorter than 195/55R15: 23.1 in vs 23.4 in (−0.37 in).
How much will my speedometer be off with 205/50R15 instead of 195/55R15?
The speedometer is calibrated for 195/55R15. With 205/50R15 it shows 60 mph when you are doing 59.0 mph, and 70 mph at 68.9 mph (−1.6%). Your speedometer also has its own factory tolerance.
Can I replace 195/55R15 with 205/50R15?
The diameter difference is −1.6%. 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.