tiresizelab.com

2021 Audi A4 Tire Fitment

2 factory tire sizes across trims — select yours below.

Trim fitment

Trim(s) OEM size
Premium 225/50R17 Specs →
Premium Plus 245/40R18 Specs →
OEM size
225/50R17
Diameter
25.86″
Sidewall
4.43″
Revs / mile
780

About 2021 Audi A4 fitment

The 2021 Audi A4 Premium ships from the factory with 225/50R17 tires, giving a 25.86″ overall diameter and 780 revs per mile. This is the reference size the factory speedometer, odometer, ABS, and TPMS were calibrated against, so any replacement tire should stay close to 25.86″ to preserve correct readings. This model year ships in multiple configurations with different OEM tire sizes (225/50R17, 245/40R18), so confirm your exact trim badge before ordering. The smallest recommended upsize is 235/40R19 — a 2.10% diameter change — which keeps the speedometer inside factory tolerance while adding marginal ride height and sidewall compliance. The most aggressive option shown, 195/50R19, runs 3.17% taller and will likely need clearance checking on stock suspension. For a direct replacement, look for brands offering 225/50R17 in all-season, highway, or terrain-appropriate compounds — the OEM spec typically emphasizes fuel economy and tread life over grip, so aftermarket replacements often unlock better wet performance or off-road capability at similar cost. Before committing to an upsize, confirm wheel-well clearance at full steering lock and suspension compression, and verify the chosen size does not conflict with snow chains, tire-fit sensors, or any lift-kit hardware already installed.

Upsize options

Size Diameter Δ vs OEM
235/40R19 26.4″ +2.10% Details →
235/45R18 26.33″ +1.81% Details →
215/55R17 26.31″ +1.75% Details →
215/50R18 26.46″ +2.34% Details →
235/50R17 26.25″ +1.52% Details →
245/50R17 26.65″ +3.05% Details →
225/40R19 26.09″ +0.88% Details →
195/50R19 26.68″ +3.17% Details →

Check speedometer error before upsizing

Type to search · try 275/65R18 or "33" for inch aliases
Common upsizes from 225/50R17:
Don't know your stock size? Load it by vehicle:

225/50R17

Diameter
25.86″ / 656.8mm
Section Width
8.86
Sidewall
4.43″ / 112.5mm
Circumference
81.24
Revs/Mile
780
See tires in 225/50R17

235/40R19

Diameter
26.4″ / 670.6mm
Section Width
9.25
Sidewall
3.7″ / 94mm
Circumference
82.94
Revs/Mile
764
See tires in 235/40R19
225/50R17 · 25.86235/40R19 · 26.4

Speedometer & Diameter Impact

Different rim — new wheels required
Diameter Change
+2.10%
Sidewall Change
-0.73″
Revs/Mile Δ
-16
mph

At an indicated 60 mph, your actual speed is 61.26 mph (98.59 km/h). Your speedometer reads 2.10% low versus actual speed.

Speedometer impact if you upsize from 225/50R17

Audi A4 — other model years