Single Size Inspector
Tire Height & Diameter Calculator
Enter any tire size code to inspect its overall height, section width, sidewall thickness, circumference, and revolutions per mile.
Dimensional Metric & Flotation Tire Height Inspector
Total Overall Tire Height
31.61 inches
802.8 mm (80.3 cm) Section Width: 10.43" 265 mm
Sidewall Height: 7.30" 185.5 mm
Circumference: 99.30" 2,522 mm
Revs Per Mile: 638 396 / km
ISO 4000-1 Tire Dimensional Equations
Sidewall Profile Equation
Sidewall height equals section width multiplied by the aspect ratio. For a 265/70R17:
265 mm × 0.70 = 185.5 mm (7.30 in).
Total Diameter Equation
Total diameter adds both top and bottom sidewalls to the inner wheel diameter:
(185.5 mm × 2) + (17 in × 25.4) = 802.8 mm (31.61 in).
Height Calculation Blueprint
Tire Height Geometry: Total height calculation requires adding upper sidewall, rim diameter, and lower sidewall: Diameter = 2×Sidewall + Rim.
ISO 4000-1 Equation
Frequently Asked Questions About Tire Height & Diameter
How do you calculate tire height from tire numbers?
Multiply the section width in millimeters by the aspect ratio percentage to calculate sidewall height in mm, divide by 25.4 to convert to inches, multiply by 2 (for both the top and bottom sidewall), and add the wheel rim diameter. Formula: Total Height = [(Width × Aspect / 100) / 25.4 × 2] + Rim Diameter.
Does wheel rim diameter determine overall tire height?
No. The wheel diameter only defines the inner hole of the tire. The total outer height is governed by the combination of wheel rim diameter plus both sidewall heights. A 275/40R20 and a 275/65R17 can have virtually identical outer heights (~28.7 inches).
How much does tread wear reduce tire height?
A new passenger or truck tire typically comes with 10/32" to 12/32" of tread depth. Wearing the tread down to the 2/32" legal minimum reduces total outer tire diameter by 0.50 to 0.62 inches (12.7 to 15.8 mm), slightly shifting speedometer readings over the tire life.
What is tire revolutions per mile (revs/mile)?
Revolutions per mile indicates how many complete 360-degree rotations a tire makes over one statutory mile (63,360 inches). It is calculated as 63,360 divided by the rolling circumference (π × Diameter). A 31.6-inch tire rotates approximately 638 times per mile.