Tire size
205/40 R17
Full dimensions and a live comparison calculator for the 205/40 R17 tire size.
Overall diameter
595.8 mm
23.46″
Sidewall height
82.0 mm
Circumference
1.872 m
Revs / km
534.3
Section width
205 mm
Aspect ratio
40%
Rim diameter
17″
431.8 mm
Radius
297.9 mm
What does 205/40 R17 mean?
The 205 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 82.0 mm. The R17 means a radial-construction tire designed for a 17-inch wheel rim. Together these give an overall diameter of 596 mm.
Compare 205/40 R17 with another size
Current Tire
New Tire
Ground line · scaled comparison
Not Recommended
Over 5% — speedometer & ABS may misread
Diameter change
+38.5 mm
6.46%
Speedometer at 100
106.5 km/h
+6.46% error
Ground clearance
+19.3 mm
ride height delta
Sidewall change
+19.3 mm
revs/km: 501.8
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/compare/205-40-r17-vs-225-45-r17Common alternatives to 205/40 R17
These sizes are within a few percent overall diameter — usually safe on the same vehicle from a speedometer-error standpoint.
Compare 205/40 R17 with popular upgrades
Plus-size upgrades from 205/40 R17
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.