235/45 R17

What size is 235/45 R17?

235/45 R17 has an overall diameter of about 25.33 in, a section width of 9.25 in and a sidewall height of 4.16 in. It turns roughly 796 times per mile. Below are the exact figures plus in-tolerance plus/minus sizes you can switch to safely.

Fitment verdict

215/55 R16 stays within the configured tolerance for 235/45 R17: -0.1% diameter and -0.1% speedometer effect.

Metric This size: 235/45 R17 Alternative: 215/55 R16 Difference Verdict
Overall diameter 25.33 in 25.31 in -0.1% Within tolerance
Section width 9.25 in 8.46 in -0.79 in Computed difference
Sidewall height 4.16 in 4.66 in +0.49 in Computed difference
Circumference 79.57 in 79.52 in -0.1% Within tolerance
Speedo 0.0% -0.1% -0.1% Within tolerance

Seasonal check

Planning a long summer drive?

Use the budget and running-cost tools before a trip, especially if the current tyres are worn or the replacement size changes diameter.

Estimate tyre budget

Specification

Overall diameter25.33 in
Section width9.25 in
Sidewall height4.16 in
Circumference79.57 in
Revolutions 495 /km · 796 /mi

In-tolerance sizes

Alternative sizes that stay within the safe diameter tolerance:

Size Diameter Speedo Verdict
215/55 R16 -0.1% -0.1% ✓ OK
235/40 R18 +0.3% +0.3% ✓ OK
195/60 R16 -0.5% -0.5% ✓ OK
225/35 R19 -0.5% -0.5% ✓ OK
215/50 R17 +0.5% +0.5% ✓ OK
235/35 R19 +0.6% +0.6% ✓ OK
205/65 R15 +0.7% +0.7% ✓ OK
225/40 R18 -0.9% -0.9% ✓ OK
255/35 R18 -1.2% -1.2% ✓ OK
195/65 R15 -1.4% -1.4% ✓ OK
225/45 R17 -1.4% -1.4% ✓ OK
245/45 R17 +1.4% +1.4% ✓ OK

Compare sizes

Looks valid
Looks valid
Units
✓ Within toleranceDiameter -0.1% (-0.02 in) · US (~3%)
  • Within tolerance · Diameter -0.1%.
  • Speedo @ 60: 60 mph60.0 mph.
  • Sidewall +0.49 in · Width -0.79 in.
Diameter-0.1%-0.02 in
Speedo @ 60-0.1%60 mph60.0 mph
Sidewall+0.49 inWidth -0.79 in
How this result is calculated

Computed from nominal tire-size geometry: diameter, circumference and speedometer error. It does not check wheel-arch, suspension or brake clearance.

Methodology
Diameter
25.33 in 25.31 in-0.02 in
Sidewall
4.16 in 4.66 in+0.49 in
Width
9.25 in 8.46 in-0.79 in
Circumference
79.57 in 79.52 in-0.1%
Revs / mile
796 797
Speedo @ 60
60 mph 60.0 mph-0.1%
Δ⌀ −0.4 mm
  • Current235/45 R17
  • New215/55 R16
  • Grounded to the road: the axle rises -0.01 in.

Result report

235/45 R17 215/55 R16 · Within tolerance

Use this size when shopping: 215/55 R16

Use this size when shopping

Geometric estimate. Always verify physical clearance (arches, suspension, brakes) before fitting.

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 215/55R16-0.1%-0.1%
OE 235/45R17+0.0%+0.0%
+1″ 155/60R18-0.0%-0.0%
+2″ 145/55R19-0.2%-0.2%

More tools

Last reviewed: 2026-06-28

Last reviewed: 2026-06-28
What changed
  • Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.