Tire Size Calculator

Enter Tire Size:
For example: 245 / 45 R 18
Overall Diameter
Tread Width
Rim Diameter
Sidewall Height
Tire Size
Tire Size
Tire Circumference

Tire Size Conversion

Tire Width Calculator

Tire width, also referred to as section width or tread width, is a crucial metric measured at its maximum thickness.

This measurement involves determining the distance between the widest points on both the inner and outer sidewalls of the tire.

By understanding tire width, one gains insight into the overall dimensions and performance characteristics of the tire.


E.g. 225/75R14: Tire Width = 225 mm (8.9 In.)

tire width

Tire Sidewall Height Calculator

Tire sidewall height, an essential parameter in tire measurements, is determined by measuring the distance from the rim to the outer edge of the tire's tread.

This measurement is typically expressed as a percentage of the tire width, providing valuable insights into the tire's proportions and characteristics.


Sidewall Height = (Tire Width*Aspect Ratio)/100

E.g. 225/75R14: Sidewall Height = (225*75)/100 = 168.8 mm (6.6 in.)

tire sidewall height

Rim/Wheel Height Calculator

The measurement of rim or wheel height entails determining the distance from the rim to the outer edge of the tire's tread.

This crucial metric is typically expressed as a percentage of the tire width, offering valuable information about the proportions and dimensions of the tire.


E.g. 225/75R14 Rim Height = 14 In.

tire rim height

Tire Diameter Calculator

Tire diameter, a fundamental dimension in tire specifications, is determined by measuring from the lowest point at the bottom to the highest point at the top of a tire.

This measurement is taken through the exact center of the tire when it is properly inflated and without any load applied.

Understanding the tire diameter provides valuable insights into the overall size and proportions of the tire, aiding in proper fitment and performance considerations.


Tire Diameter = Rim Height + 2*Sidewall Height

E.g. 225/75R14: Tire Diameter = 14 + 2*6.6 = 27.3 In.

tire diameter

Tire Circumference Calculator

Tire circumference is the measurement of the total distance covered by a tire during a complete revolution.

This crucial metric provides valuable information about the tire's size and the amount of ground it covers with each rotation.

Understanding tire circumference aids in various applications, including speed calculations, odometer accuracy, and overall tire performance assessment.


Circumference = Tire Diameter x 3.14

E.g. 225/75R14: Circumference = 27.3*3.14 = 85.7 In.

tire circumference

Tire Revolutions Calculator

Revolutions per mile, often referred to as "revs/mile," serve as a performance indicator for tires.

This metric quantifies the number of complete rotations a tire makes while traveling a distance of one mile.

By measuring revs/mile, one can assess the tire's efficiency and evaluate its suitability for various applications.


Revs/mile = 63,360/Circumference

225/75R14: Revs/mile = 63,360/85.7 = 739.1

tire revolution

FAQs About Tire Size Calculator

Why is tire width important?

Tire width is crucial as it directly impacts the handling, traction, and overall performance of a vehicle.

The width of a tire affects its contact patch with the road, influencing stability and grip in various driving conditions.

What is tire aspect ratio?

Tire aspect ratio refers to the numerical value that represents the height of the tire's sidewall as a percentage of its width.

It influences the tire's performance characteristics, including ride comfort, handling responsiveness, and overall road grip.

What is an acceptable difference in tire sizes?

When it comes to tire size differences, it is generally recommended to maintain a minimal variance to ensure proper handling and vehicle performance.

A variance of 3% or less in overall tire diameter is commonly considered acceptable.

How does wheel size differ from tire size?

Wheel size refers to the diameter of the wheel itself, while tire size indicates the dimensions of the tire mounted on the wheel.

The wheel size is typically measured from bead seat to bead seat, while the tire size specifies width, aspect ratio, and rim diameter.

Both factors are essential and should be considered when selecting tires and wheels for a vehicle.

How can a tire size calculator help me choose the right tires?

A tire size calculator is a valuable tool that assists in selecting the right tires for your vehicle.

By inputting details such as the current tire size or desired tire specifications, the calculator can generate recommended tire sizes that are compatible with your vehicle.

This helps ensure proper fitment, optimal performance, and accurate speedometer readings.

Related Tire Size Conversion

Tire SizeDiameterRim
225/75R1730.317 x 6.0-7.5
275/45R1625.716 x 8.5-10.5
275/30R2228.522 x 9.0-10.0
245/40R1724.717 x 8.0-9.5
195/35R1823.418 x n/a
255/45R172617 x 8.0-9.5
185/55R132113 x n/a
125/70R1925.919 x n/a
245/60R1728.617 x 7.0-8.5
155/70R1725.517 x n/a
295/40R1726.317 x 10.0-11.5
225/35R1925.219 x 7.5-9.0
155/70R1523.515 x 4.0-5.0
305/35R1927.419 x 10.0-12.0
315/50R2032.420 x 8.5-11.0
305/25R192519 x 10.5-11.5
205/50R1321.113 x 5.5-7.5
225/40R1421.114 x 7.5-9.0
305/40R2231.622 x 10.0-12.0
195/40R1723.117 x 6.5-7.5
165/90R1829.718 x n/a
315/25R2026.220 x 11.0-12.0
275/50R2030.820 x 7.5-9.5
345/85R1639.116 x n/a
235/35R2026.520 x 8.0-9.5
265/30R1824.318 x 9.0-10.0
245/60R1526.615 x 7.0-8.5
355/25R212821 x 12.5-13.5
175/80R182918 x n/a
365/70R1636.116 x n/a
285/45R2232.122 x 9.0-10.5
235/35R2127.521 x n/a
345/35R1524.515 x 11.5-13.5
245/70R1730.517 x 6.5-8.0
185/50R1522.315 x n/a
255/60R183018 x 7.0-9.0
165/80R1525.415 x 4.0-5.5
215/35R1722.917 x 7.0-8.5
295/30R202720 x 10.0-11.0
315/45R2132.221 x n/a
225/65R1728.517 x 6.0-8.0
165/50R1521.515 x 4.5-6.0
135/80R1220.512 x 3.5-4.5
205/65R1626.516 x 5.5-7.5
275/60R142714 x 7.5-9.5
245/50R1524.615 x 6.5-7.5
285/40R192819 x 9.5-11.0
305/55R2033.220 x 8.5-10.0
225/45R162416 x 7.0-8.5
305/45R1727.817 x 9.5-11.5
295/50R1526.615 x 8.0-10.5
245/50R2029.620 x 7.0-8.5
235/75R1528.915 x 6.0-8.0
235/75R1629.916 x 6.0-8.0
215/60R1525.215 x 6.0-7.5
195/70R1424.714 x 5.0-6.5
255/40R212921 x 8.5-10.0
155/80R1726.817 x n/a
255/65R1831.118 x 7.0-9.0
165/90R1728.717 x n/a