Tire size comparison
225/35R19 vs 225/40R19
225/40R19 is +3.5% taller than 225/35R19: 26.1 in vs 25.2 in (+0.89 in), and the same width. With 225/40R19 on a vehicle set up for 225/35R19, 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 (225/40R19 instead of 225/35R19) · 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
225/35R19 vs 225/40R19: full comparison
| 225/35R19 | 225/40R19 | Difference | |
|---|---|---|---|
| Overall diameter | 25.20 in | 26.09 in | +0.89 in (+3.5%) |
| Width | 8.86 in | 8.86 in | ±0.00 in (±0.0%) |
| Sidewall height | 3.10 in | 3.54 in | +0.44 in |
| Circumference | 79.2 in | 82.0 in | +2.8 in |
| Revs per mile (nominal) | 800 | 773 | −27 |
| Wheel diameter | 19 in | 19 in | ±0 in |
| Diameter in mm | 640 | 663 | +22 mm |
Speedometer difference
Your speedometer is calibrated for 225/35R19. Fitted with 225/40R19, the actual speed is the reading × 26.09 ÷ 25.20.
| Speedometer shows | Actual speed | Difference |
|---|---|---|
| 20 mph | 20.7 mph | +0.7 mph |
| 30 mph | 31.1 mph | +1.1 mph |
| 45 mph | 46.6 mph | +1.6 mph |
| 55 mph | 56.9 mph | +1.9 mph |
| 60 mph | 62.1 mph | +2.1 mph |
| 70 mph | 72.5 mph | +2.5 mph |
| 80 mph | 82.8 mph | +2.8 mph |
Real tires: published diameters
225/35R19: 25–25.4 in published by 5 makers; 225/40R19: 25.8–26.3 in published by 6 makers. Calculated figures assume a nominal tire; the exact difference between two specific tires depends on their models.
More about each size: 225/35R19 · 225/40R19
Related comparisons
FAQ
Which is bigger, 225/35R19 or 225/40R19?
225/40R19 is +3.5% taller than 225/35R19: 26.1 in vs 25.2 in (+0.89 in).
How much will my speedometer be off with 225/40R19 instead of 225/35R19?
The speedometer is calibrated for 225/35R19. With 225/40R19 it shows 60 mph when you are doing 62.1 mph, and 70 mph at 72.5 mph (+3.5%). Your speedometer also has its own factory tolerance.
Can I replace 225/35R19 with 225/40R19?
The diameter difference is +3.5%. 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.