Tire size comparison
265/70R17 vs 35x12.50R17
35x12.50R17 is +10.7% taller than 265/70R17: 35.0 in vs 31.6 in (+3.39 in), and 2.1 in wider. With 35x12.50R17 on a vehicle set up for 265/70R17, the speedometer shows 60 mph at an actual 66.4 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 (35x12.50R17 instead of 265/70R17) · 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
265/70R17 vs 35x12.50R17: full comparison
| 265/70R17 | 35x12.50R17 | Difference | |
|---|---|---|---|
| Overall diameter | 31.61 in | 35.00 in | +3.39 in (+10.7%) |
| Width | 10.43 in | 12.50 in | +2.07 in (+19.8%) |
| Sidewall height | 7.30 in | 9.00 in | +1.70 in |
| Circumference | 99.3 in | 110.0 in | +10.7 in |
| Revs per mile (nominal) | 638 | 576 | −62 |
| Wheel diameter | 17 in | 17 in | ±0 in |
| Diameter in mm | 803 | 889 | +86 mm |
Speedometer difference
Your speedometer is calibrated for 265/70R17. Fitted with 35x12.50R17, the actual speed is the reading × 35.00 ÷ 31.61.
| Speedometer shows | Actual speed | Difference |
|---|---|---|
| 20 mph | 22.1 mph | +2.1 mph |
| 30 mph | 33.2 mph | +3.2 mph |
| 45 mph | 49.8 mph | +4.8 mph |
| 55 mph | 60.9 mph | +5.9 mph |
| 60 mph | 66.4 mph | +6.4 mph |
| 70 mph | 77.5 mph | +7.5 mph |
| 80 mph | 88.6 mph | +8.6 mph |
Real tires: published diameters
265/70R17: 31.5–32 in published by 6 makers; 35x12.50R17: 34.5–35.1 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: 265/70R17 · 35x12.50R17
Related comparisons
FAQ
Which is bigger, 265/70R17 or 35x12.50R17?
35x12.50R17 is +10.7% taller than 265/70R17: 35.0 in vs 31.6 in (+3.39 in).
How much will my speedometer be off with 35x12.50R17 instead of 265/70R17?
The speedometer is calibrated for 265/70R17. With 35x12.50R17 it shows 60 mph when you are doing 66.4 mph, and 70 mph at 77.5 mph (+10.7%). Your speedometer also has its own factory tolerance.
Can I replace 265/70R17 with 35x12.50R17?
The diameter difference is +10.7%. 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.