265/30R22 tire size explained
Every digit in 265/30R22 decoded: section width, aspect ratio, rim diameter, and the derived overall diameter and revolutions per mile that your speedometer and TPMS calibrations depend on.
The size string, decoded
(mm) / 30aspect ratio
(% of width) R 22rim diameter
(inches)
Computed dimensions
| Section width | 265 mm (10.43 in) |
|---|---|
| Aspect ratio | 30% (sidewall = 30% of width) |
| Rim diameter | 22 in (558.8 mm) |
| Sidewall height | 79.5 mm (3.13 in) |
| Overall diameter | 717.8 mm (28.26 in) |
| Circumference | 2255 mm (88.78 in) |
| Revolutions per mile | 714 revs/mi |
Overall diameter is the single most important number for fitment compatibility, because it determines how far the tire travels per revolution. Speedometer, odometer, TPMS rev/mile calibration, ABS rotational reference, and AWD viscous coupling all consume overall diameter (directly or indirectly). Per ETRTO 2024 §2.3, the formula is:
overall_diameter_mm = rim_inches × 25.4 + 2 × (width_mm × aspect_percent / 100)
For 265/30R22, this resolves to 22 × 25.4 + 2 × (265 × 30 / 100) = 558.8 + 159.0 = 717.8 mm.
Try changing the numbers
The calculator below mirrors the same formula your speedometer and ABS modules use. Edit any field to see how the dimensions move.
For full safe-alternative analysis use the tire compatibility calculator. To explore upsize and downsize options for 265/30R22, see 265/30R22 alternatives.
Where 265/30R22 shows up
265/30R22 is a valid passenger-tire size under ETRTO and ISO 4000-1, but does not currently appear as an OEM fitment on any vehicle in our catalog. This combination is sometimes used as a plus-size or replacement option rather than an OEM specification.
This is the same data the size's reverse-lookup page renders in table form. The explained page tells you what the size means; the reverse-lookup page tells you what cars use it.
What changes if any of the numbers move
Width up 10 mm (e.g. 265 → 275): contact patch widens, dry grip and steering load both increase, fuel economy drops slightly. Overall diameter rises 6.0 mm.
Aspect down 5 points (e.g. 30 → 25): sidewall shortens by 13.3 mm, steering sharpens, ride harshness rises, pothole risk increases. Overall diameter drops by twice that.
Rim up 1 inch (e.g. 22 → 23): rim diameter rises 25.4 mm. To preserve overall diameter (the standard "plus-1" pattern), drop aspect by ~10 points and add ~10 mm of width simultaneously. See the plus-size calculator for the math.
What the R means: radial construction
The R between aspect and rim diameter indicates radial construction: the tire's internal cords run perpendicular to the direction of travel, from bead to bead. The alternative is bias-ply construction (denoted by D, B, or no letter at all), where cords run diagonally and stack on each other. Radial tires dominate the passenger-tire market because they give a longer-lived contact patch, lower rolling resistance, and better high-speed stability. Bias-ply survives in specialty applications: trailer tires (where the stiffer sidewall is an advantage), some agricultural and classic-vehicle restorations, and occasional motorcycle fitments. The R designation has been standard on US-market passenger tires since the late 1970s and is mandatory on every modern car tire under FMVSS 109.
You'll occasionally see ZR in older size strings (e.g. 225/45ZR17). The Z signifies the tire is rated above 240 km/h (149 mph) — historically the highest speed rating before V, W, and Y were added to the ladder. On current tires the speed rating is encoded separately after the load index, but the ZR notation persists on legacy and high-performance models.
What's NOT in the size string
The width-aspect-rim trio defines geometry only. Several other critical specifications appear elsewhere on the sidewall and matter just as much for fitment compatibility:
- Load index — a 2- or 3-digit number after the size (e.g. 225/65R17 102 H) that maps to a maximum-weight rating per Tire & Rim Association 2025 Table 1-2. An OEM replacement must equal or exceed the original load index.
- Speed rating — a single letter after the load index (e.g. 265/30R22 102 H) on the ETRTO ladder (S=180, T=190, U=200, H=210, V=240, W=270, Y=300 km/h). Replacement should match or exceed the placard speed rating.
- OEM approval markings — small letters next to the size: T0 (Tesla), MO and MO-S (Mercedes), * (BMW), N0/N1/N2/N3/N4 (Porsche), F (Ford performance), AO (Audi), VOL (Volvo), J (Jaguar). These signal the tire was developed against that manufacturer's specifications.
- HL (high load) — appears before the width on many EV tires (e.g. HL235/45R20). Indicates the tire carries a higher load index than the standard XL designation, required for the additional mass of battery-electric vehicles.
- DOT date code — a 4-digit code at the end of the DOT string (e.g. "DOT XYZ1 ABC2 4724") indicates the week and year of manufacture (here, the 47th week of 2024). Tires older than 6 years from the date code carry sidewall degradation risk regardless of tread depth.
The tire sidewall codes guide walks through every marking position on a typical sidewall.
Sources & methodology
Last verified 2026-05-17 against the standards below.
- ETRTO 2024 Standards Manual §2.3 (section width, aspect ratio, overall diameter formula). European Tyre and Rim Technical Organisation, Brussels.
- Tire & Rim Association 2025 Yearbook (North American passenger tire dimensions and load index reference). T&RA, Copley OH.
- ISO 4000-1:2021 Passenger car tyres and rims — Part 1: Tyre designations. International Organization for Standardization.
- SAE J1349 (speedometer accuracy tolerance).