235/40 R18 vs 245/35 R19

245/35 R19 stays within the configured tolerance for 235/40 R18: +1.4% diameter and +1.4% speedometer effect.

Geometric comparison

245/35 R19 stays within the configured tolerance for 235/40 R18: +1.4% diameter and +1.4% speedometer effect.

Geometric comparison
Metric	This size: 235/40 R18	Alternative: 245/35 R19	Difference	Verdict
Overall diameter	25.40 in	25.75 in	+1.4%	Within tolerance
Section width	9.25 in	9.65 in	+0.39 in	Computed difference
Sidewall height	3.70 in	3.38 in	-0.32 in	Computed difference
Circumference	79.80 in	80.90 in	+1.4%	Within tolerance
Speedo	0.0%	+1.4%	+1.4%	Within tolerance

Compare sizes

Current tireLooks valid

New tireLooks valid

Market

Units

Minor variationWithin tolerance · Diameter +1.4% (+0.35 in) · US (~3%)

Minor variation · This rating covers tire geometry only, not vehicle compatibility.
Diameter +1.4% · Ride-height change +0.18 in.
Speedometer reads low · 60 mph → 60.8 mph.
Sidewall -0.32 in · Width +0.39 in.

Diameter+1.4%+0.35 in

Speedo @ 60+1.4%60 mph → 60.8 mph

Sidewall-0.32 inWidth +0.39 in

Ride-height change+0.18 inDiameter ÷ 2

How this result is calculated

Computed from nominal tire-size geometry: diameter, circumference and speedometer error. It does not check vehicle placard approval, load/speed rating, rim-width range, wheel-arch, suspension or brake clearance.

Methodology

Before fitting

Check the vehicle placard and owner’s manual first.
Match or exceed the required load index and speed rating.
Confirm rim-width range, bolt pattern, hub bore, offset and fasteners.
Inspect wheel-arch, suspension and brake clearance under real vehicle load.
Check TPMS, cold pressure and local roadworthiness rules.

Diameter: 25.40 in 25.75 in+0.35 in
Sidewall: 3.70 in 3.38 in-0.32 in
Width: 9.25 in 9.65 in+0.39 in
Circumference: 79.80 in 80.90 in+1.4%
Revs / mile: 794 783
Speedo @ 60: 60 mph 60.8 mph+1.4%
Ride-height change: 0.00 in +0.18 in
True distance per 100 indicated: 100 mi 101.4 mi+1.4%

Current — 235/40 R18
New — 245/35 R19
Grounded to the road: the axle rises +0.18 in.

Result report

235/40 R18 245/35 R19 · Minor variation · Within tolerance

Plan budget for this size: 245/35 R19

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Plan budget for this size

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Markdown link

[235/40 R18 vs 245/35 R19 Tire size comparison](https://tirefitlab.com/tire-size-calculator/?from=235%2F40+R18&to=245%2F35+R19&market=us)

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Budget$125–$175Per tire Mid-range$160–$230Per tire Premium$230–$325Per tire

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

In-tolerance alternative sizes

In-tolerance alternative sizes
Size	Diameter	Speedo @ 100	Use this
OE `235/40R18`	+0.0%	+0.0%

235/40 R18 · 245/35 R19 · Methodology

Technical check: 2026-06-28

What changed

Checked generated routes, metadata, sitemap inclusion and localized page rendering.

Methodology