Tire size
305/40 R22
Full dimensions and a live comparison calculator for the 305/40 R22 tire size.
Overall diameter
802.8 mm
31.61″
Sidewall height
122.0 mm
Circumference
2.522 m
Revs / km
396.5
Section width
305 mm
Aspect ratio
40%
Rim diameter
22″
558.8 mm
Radius
401.4 mm
What does 305/40 R22 mean?
The 305 is the section width in millimetres, measured sidewall to sidewall. The 40 is the aspect ratio — sidewall height as a percentage of width, so the sidewall here is 122.0 mm. The R22 means a radial-construction tire designed for a 22-inch wheel rim. Together these give an overall diameter of 803 mm.
Compare 305/40 R22 with another size
Current Tire
New Tire
Ground line · scaled comparison
Not Recommended
Over 5% — speedometer & ABS may misread
Diameter change
-168.5 mm
-20.99%
Speedometer at 100
79.0 km/h
-20.99% error
Ground clearance
-84.3 mm
ride height delta
Sidewall change
-20.8 mm
revs/km: 501.8
Permalink for this comparison:
/compare/305-40-r22-vs-225-45-r17Common alternatives to 305/40 R22
These sizes are within a few percent overall diameter — usually safe on the same vehicle from a speedometer-error standpoint.
Fitment safety note
Overall diameter, speedometer error and circumference are only part of the picture. Physical clearance, wheel offset (ET), hub bore, suspension geometry, load index and your manufacturer's recommendation all decide whether a size is truly safe on your car. Always cross-check with the vehicle manual or a qualified fitter before changing tire size.