How it works

TireFlows

Get diameter, speedometer impact, and alternate sizes — free, no signup.

Try
/R

Result

Diameter

27.04"

Calculated from size marking (math only) — not a fitment guarantee. How it works

Alternate Tire Sizes

Closest diameters (math only · same rim · within 3%)

Tap a size to compare it with your current size

235/50R18+0.8%245/45R18-1.31%265/45R18+1.31%275/40R18-1.38%245/50R18+2.26%265/40R18-2.55%235/45R18-2.62%275/45R18+2.62%
Width 10.04 ″Rim 18 ″Dia. 27.04 ″4.52 ″Revs/Mile 746.0Circum. 84.9″
Diameter27.04"
Width10.04"
Sidewall4.52"
Circum.84.934"
Revs/Mile746

How results are calculated

Tire dimensions are calculated from the metric size format (width / aspect ratio / rim diameter). Diameter, circumference, and revolutions per mile are derived mathematically — no fitment or vehicle data is used.

The 3% rule is a general reference for acceptable diameter difference, not a guarantee. Always check your vehicle manual or consult a tire professional.

How it works