According to Subaru's specification sheets, the Outback uses 225/65R17 or 225/60R18 from 2015 to 2025. The Forester uses 225/60R17 or 225/55R18 from 2014 to 2024, with 235/50R19 added in 2025. The Crosstrek uses 225/55R17 from 2013 to 2017 and 225/60R17 or 225/55R18 from 2018. The WRX uses 235/45R17 and 245/40R18, with 245/35R19 on some years. The 2014 Forester is 225/60R17 or 225/55R18, the 2015 Outback is 225/65R17 or 225/60R18, the 2016 Crosstrek is 225/55R17, and the 2019 sizes are Outback 225/65R17, Forester 225/60R17 and Crosstrek 225/60R17. Subaru's owner's manual requires all four tires to be the same size, circumference, construction, brand and load range. As a rule of thumb this calculator flags a diameter difference above about 1%.
QUICK ANSWER
Per Subaru's specification sheets, the 2015–2025 Subaru Outback uses 225/65R17 (28.52″ OD) or 225/60R18. The 2014–2024 Forester uses 225/60R17 or 225/55R18. The 2025–2026 WRX uses 245/40R18 or 245/35R19. Subaru's owner's manual requires all four tires to be the same size, brand and construction with matching wear, so replace all four together.
| Model / Years | Stock Size | OD | Owner-reported Upgrade |
|---|---|---|---|
| 2015–2025 Outback | 225/65R17 | 28.52″ | 235/65R17 (+0.51″) |
| 2014–2024 Forester | 225/60R17 | 27.63″ | 225/65R17 (+0.89″) |
| 2018–2026 Crosstrek | 225/60R17 | 27.63″ | 225/65R17 (+0.89″) |
| 2025–2026 WRX | 245/40R18 | 25.72″ | Stay near the stock diameter |
| 2022–2026 Outback Wilderness (all-terrain) | 225/65R17 | 28.52″ | Factory all-terrain size |
| 2018–2021 WRX STI Limited | 245/35R19 | 25.75″ | Stay near the stock diameter |
Sizes and diameters are from Subaru's specification sheets (US market). The upgrade column is owner-reported, not a Subaru specification. Always replace all four tires together on Subaru AWD.
Subaru Tire Size Difference Calculator
Common Subaru size swaps
Subaru Tire Size by Year (2013–2026)
Every tire size Subaru lists for the four most popular models in each year, from its US specification sheets. Which size your car has depends on the trim, so confirm it on the door pillar label or with the OEM Lookup tab above.
| Year | Outback | Forester | Crosstrek | Impreza |
|---|---|---|---|---|
| 2013 | 215/70R16, 225/60R17 | n/a | 225/55R17 | 195/65R15, 205/55R16, 205/50R17 |
| 2014 | 215/70R16, 225/60R17 | 225/60R17, 225/55R18 | 225/55R17 | 195/65R15, 205/55R16, 205/50R17 |
| 2015 | 225/65R17, 225/60R18 | 225/60R17, 225/55R18 | 225/55R17 | 195/65R15, 205/55R16, 205/50R17 |
| 2016 | 225/65R17, 225/60R18 | 225/60R17, 225/55R18 | 225/55R17 | 195/65R15, 205/55R16, 205/50R17 |
| 2017 | 225/65R17, 225/60R18 | 225/60R17, 225/55R18 | 225/55R17 | 205/55R16, 205/50R17, 225/40R18 |
| 2018 | 225/65R17, 225/60R18 | 225/60R17, 225/55R18 | 225/60R17, 225/55R18 | 205/55R16, 205/50R17, 225/40R18 |
| 2019 | 225/65R17, 225/60R18 | 225/60R17, 225/55R18 | 225/60R17, 225/55R18 | 205/55R16, 205/50R17, 225/40R18 |
| 2020 | 225/65R17, 225/60R18 | 225/60R17, 225/55R18 | 225/60R17, 225/55R18 | 205/55R16, 205/50R17, 225/40R18 |
| 2021 | 225/65R17, 225/60R18 | 225/60R17, 225/55R18 | 225/60R17, 225/55R18 | 205/55R16, 205/50R17, 225/40R18 |
| 2022 | 225/65R17 (also all-terrain), 225/60R18 | 225/60R17 (also all-terrain), 225/55R18 | 225/60R17, 225/55R18 | 205/55R16, 205/50R17, 225/40R18 |
| 2023 | 225/65R17 (also all-terrain), 225/60R18 | 225/60R17 (also all-terrain), 225/55R18 | 225/60R17, 225/55R18 | 205/55R16, 205/50R17, 225/40R18 |
| 2024 | 225/65R17 (also all-terrain), 225/60R18 | 225/60R17 (also all-terrain), 225/55R18 | 225/60R17 (also all-terrain), 225/55R18 | 205/55R16, 225/40R18 |
| 2025 | 225/65R17 (also all-terrain), 225/60R18 | 225/60R17 (also all-terrain), 225/55R18, 235/50R19 | 225/60R17 (also all-terrain), 225/55R18 | 205/55R16, 225/40R18 |
| 2026 | 225/65R17 (all-terrain), 225/60R18, 225/55R19 | 225/60R17, 235/60R17 (all-terrain), 225/55R18, 235/50R19 | 225/60R17 (also all-terrain), 225/55R18 | 225/40R18 |
Base trim only. Higher trims (Limited, Touring, XT, Sport, Wilderness, STI) use larger diameters: see the full OEM Lookup tab. "n/a" indicates model not yet available that year. The Subaru tire size guide by model covers AWD rules, stock diameters and upgrade rules in more detail.
Subaru Tire Size Formulas
Overall Diameter (OD): OD (in) = Rim diameter (in) + 2 × [Section width (mm) × Aspect ratio / 100 / 25.4]
Example: 225/65R17: OD = 17 + 2 × (225 × 0.65 / 25.4) = 17 + 2 × 5.759 = 28.52 inches
OD Difference %: Δ% = (New OD − Stock OD) / Stock OD × 100
Subaru AWD: Subaru's owner's manual asks for the same size, circumference, construction, brand and load range on all four tires and publishes no percentage.
Speedometer Correction: True speed = Indicated speed × (New OD / Stock OD)
Sidewall Height (in): SW = (Width mm × Aspect ratio / 100) / 25.4
Circumference: C = π × OD (inches)
How to Use This Calculator
- 1
Select your Subaru model in OEM Lookup
Click your model name (Outback, Forester, Crosstrek, Impreza, Legacy, WRX, BRZ, Ascent, or Solterra). Every OEM tire size Subaru lists for that model appears by year, with the rim size and overall diameter.
- 2
Use Size Diff to check your swap
Enter your current (stock) tire code and your proposed new size in the Size Diff tab. Click Calculate Difference to see OD delta, AWD note, sidewall comparison, and speedometer correction table.
- 3
Read the AWD note
The badge says whether the two sizes have the same diameter, or differ and by how much against the 3% limit in Continental's guidance. Subaru's owner's manual requires all four tires to be the same size, circumference, construction, brand and load range and gives no percentage.
- 4
Browse lifted tire sizes
Open the Lifted Sizes tab and select your model for owner-reported fitments: stock size, 1-inch lift, 2-inch lift, maximum all-terrain size, max OD, and a typical wheel offset. Subaru does not publish or approve these sizes.
- 5
Find your tire pressure
Open the Pressure tab. Subaru does not publish a pressure per model, so the tab shows where to read the correct cold pressure for your car: the tire inflation pressure label on the driver's door pillar.
- 6
Use the full Size Chart for a complete overview
The Size Chart tab lists every OEM fitment in Subaru's specification sheets across all models and years. Filter by model name or expand to show all rows. Use the sticky-header table to cross-reference years.
What Subaru Says About Tire Size on AWD
Subaru's owner's manual is direct about the requirement: all four tires should be the same size, circumference, construction, brand and load range, and for the stability control system the amount of wear should be the same on all four. Subaru does not publish a percentage tolerance. When you change size, replace all four tires together and check the new size against the old one before you buy.
To compare two sizes as a percentage, the AWD diameter tolerance calculator takes any pair, the AWD tire size mismatch guide lists what other makers say, and the spare tire compatibility chart covers spares on AWD vehicles.
How to Find Your Subaru Tire Size by VIN
Your Subaru's exact OEM tire size is on the tire placard and inflation pressure label on the driver's door pillar, not in the VIN digits themselves. The labels show the OEM size and the recommended cold inflation pressure for your specific build. If you've purchased a used Subaru and the tires don't match the label, verify the actual rim diameter before ordering: rim diameters changed across generations (for example the Crosstrek moved from a 17″ wheel in 2013–2017 to 17″ and 18″ options from 2018). The safest method to confirm your exact size is: (1) check the door pillar label, (2) look at the sidewall of the current tires, (3) cross-reference with the OEM Lookup table above using your model and year.