Decoded sidewall size
235/50R18 tire size
235/50R18 in inches: 27.25" overall diameter — 9.25" wide, 4.63" sidewall.
Methodology: dimensions are calculated from standard ETRTO tire-size formulas. Last reviewed June 2026 by the TreadSize editorial team.
Before you fit 235/50R18: verify the vehicle placard, load index, speed rating, wheel offset, and full-lock/full-compression clearance. Nominal dimensions do not guarantee a safe physical fit.
Compare this sizeFull dimensions
| Measurement | Metric | Imperial |
|---|---|---|
| Overall diameter | 692.2 mm | 27.25 in |
| Section width | 235 mm | 9.25 in |
| Sidewall height | 117.5 mm | 4.63 in |
| Rim diameter | 457.2 mm | 18 in |
| Circumference | 2174.6 mm | 85.61 in |
| Revolutions per mile | 740.1 | |
| Aspect ratio | 50% | |
NHTSA safety record for 235/50R18
Drawn from official U.S. government (NHTSA) consumer complaint and recall filings for this exact tire size — not the generic averages you'll find elsewhere.
2 tire recalls on record affecting 235/50R18
- NHTSA 22T021000 · 2022 BRIDGESTONE TURANZA EL440 Damaged tires can lead to a sudden loss of air pressure and loss of vehicle control, increasing the risk of a crash.
- NHTSA 12T023000 · 2012 VOGUE SIGNATURE V In the event of a safety recall, tires missing a TIN from the outboard sidewall cannot be readily identified.
What owners report fails — 235/50R18
- Tread separation 11
- Blowout 5
- Road hazard 2
- Cracking 2
These are unverified consumer reports and manufacturer recalls filed with the National Highway Traffic Safety Administration — not validated failure rates, and not adjusted for how many tires of this size are in service. Popular sizes naturally accumulate more reports. Use this as a research signal, not a verdict on any specific tire. Data as of 2021. Source: NHTSA Office of Defects Investigation (public domain). Always check the latest recalls at NHTSA.gov and report a tire problem if you have one.
Recall timeline for 235/50R18
NHTSA campaigns affecting this tire size, grouped from the local recall dataset. Exact owner-notification dates are not stored here; open the campaign at NHTSA for current remedy details.
How 235/50R18 compares inside the NHTSA size dataset
This comparison is derived only from tire sizes that have a real NHTSA complaint or recall record in the TreadSize dataset. Source: NHTSA ODI — Consumer Complaints (FLAT_CMPL) + Recalls (FLAT_RCL), U.S. DOT public domain; Complaints through 2021.
Nearby safety records by complaint volume
Dataset download: JSON or CSV. Latest recall lookup: NHTSA.gov.
Related tire sizes
Frequently asked questions
What is the overall diameter of a 235/50R18 tire?
A 235/50R18 tire has an overall diameter of 27.25 inches (692.2 mm).
How tall is a 235/50R18 tire?
The sidewall height is 117.5 mm (4.63 inches), and the overall diameter from the ground to the top of the tire is 27.25 inches.
How many revolutions per mile does a 235/50R18 tire make?
A 235/50R18 tire makes approximately 740 revolutions per mile. Your speedometer is calibrated to this number.
What rim size does a 235/50R18 tire fit?
A 235/50R18 tire is designed for a 18-inch rim (457.2 mm).
Are there recalls or safety complaints for 235/50R18 tires?
NHTSA has 26 consumer complaints on record for the 235/50R18 size and 2 recalls; the most reported issue is tread separation (11 reports). These are unverified consumer reports, not validated failure rates, and are not adjusted for how many tires of this size are in service.
All dimensions calculated using standard ETRTO formulas. Always confirm fitment with your vehicle's door-placard and a qualified tire professional before purchasing.