215/50R18 vs 315/30R19 tire size comparison
315/30R19 is 0.1 in (0.09%) shorter than 215/50R18 and 3.9 in wider. They fit different wheels: 215/50R18 an 18-inch wheel and 315/30R19 a 19-inch wheel.
215/50R18 and 315/30R19 side by side
| Measurement | 215/50R18 | 315/30R19 | Difference | Difference % |
|---|---|---|---|---|
| Section width | 8.5 in (215 mm) | 12.4 in (315 mm) | +3.9 in (+100 mm) | +46.51% |
| Sidewall height | 4.2 in (108 mm) | 3.7 in (95 mm) | -0.5 in (-13 mm) | -12.09% |
| Wheel (rim) diameter | 18.0 in (457 mm) | 19.0 in (483 mm) | +1.0 in (+26 mm) | +5.56% |
| Overall diameter | 26.5 in (672 mm) | 26.4 in (672 mm) | -0.1 in (0 mm) | -0.09% |
| Circumference | 83.1 in (2112 mm) | 83.1 in (2110 mm) | 0.0 in (-2 mm) | -0.09% |
| Revolutions per mile | 762 | 763 | +1 | +0.09% |
Differences are 315/30R19 minus 215/50R18; percentages are relative to 215/50R18. These are nominal design dimensions. Real tires vary by brand, tread depth, wheel width, load and pressure.
The overall diameter differs by 0.09%, which is within the common 3% rule of thumb.
The rule of thumb keeps a replacement size within about 3% of the original overall diameter. It covers diameter only. It is not a fit, load or safety check, because width, wheel diameter, load capacity and clearance matter too. Confirm any size change with your vehicle's owner's manual or a tire professional.
Speedometer difference
When the speedometer reads 60 mph on a vehicle built for 215/50R18, the actual speed on 315/30R19 is about 59.9 mph. When it reads 60 mph on a vehicle built for 315/30R19, the actual speed on 215/50R18 is about 60.1 mph. These figures assume the speedometer is accurate on the original size and use nominal dimensions, so treat them as estimates.
| Speedometer reads | Actual on 315/30R19 (built for 215/50R18) | Actual on 215/50R18 (built for 315/30R19) |
|---|---|---|
| 20 mph | 20.0 mph | 20.0 mph |
| 30 mph | 30.0 mph | 30.0 mph |
| 40 mph | 40.0 mph | 40.0 mph |
| 50 mph | 50.0 mph | 50.0 mph |
| 60 mph | 59.9 mph | 60.1 mph |
| 70 mph | 69.9 mph | 70.1 mph |
| 80 mph | 79.9 mph | 80.1 mph |
A common rule of thumb is to keep a replacement size within about 3% of the original overall diameter. Check the tire placard on the driver's door jamb and your owner's manual for the sizes your vehicle was built for. Confirm any size change with your vehicle's owner's manual or a tire professional.
Which vehicles use each size?
These vehicles list the size among their verified sizes, by trim. Open one to see all of its sizes.
Check it in the calculator
The calculator takes the same two sizes and shows the full comparison, or lets you swap either one for another size.
Open this comparison in the calculatorShop for 215/50R18 or 315/30R19 tires
Confirm the size on your tire sidewall or door placard first. These links open each store's own search; prices and stock are on their sites.
215/50R18
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Other comparisons with 215/50R18
Side-by-side dimensions and speedometer difference for sizes close to 215/50R18 in overall diameter.
- 215/50R18 vs 235/35R20+0.04% taller than 215/50R18
- 205/65R16 vs 215/50R18+0.10% taller than 215/50R18
- 215/50R18 vs 275/30R20+0.12% taller than 215/50R18
- 215/50R18 vs 235/40R19-0.24% shorter than 215/50R18
- 215/50R18 vs 275/35R19+0.43% taller than 215/50R18
Other comparisons with 315/30R19
Side-by-side dimensions and speedometer difference for sizes close to 315/30R19 in overall diameter.
- 235/35R20 vs 315/30R19+0.13% taller than 315/30R19
- 205/65R16 vs 315/30R19+0.19% taller than 315/30R19
- 275/30R20 vs 315/30R19+0.21% taller than 315/30R19
- 235/45R18 vs 315/30R19-0.43% shorter than 315/30R19
- 245/45R18 vs 315/30R19+0.91% taller than 315/30R19
You might also need
- Digital tire pressure gauge (Amazon search, opens in a new tab)
Check your tire pressure against the number on your door placard.
- Portable tire inflator (Amazon search, opens in a new tab)
Top up a low tire at home without a trip to the gas station.
- Tire tread depth gauge (Amazon search, opens in a new tab)
Measure how much tread is left before you decide to replace.
- Lug wrench or torque wrench (Amazon search, opens in a new tab)
Useful for rotations and tire changes; follow the torque spec in your owner's manual.
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