Our handy motorcycle tire size calculator helps riders compare tire sizes including tire’s width, aspect ratio, construction type, and rim diameter.
For example, a tire size of 120/70-17 can be broken down as follows:
- 120: Width of the tire in millimeters
- 70: Aspect ratio (height as a percentage of width)
- 17: Rim diameter in inches
Motorcycle Tyre Size Calculator
| Original Size | New Size | Diameter Difference | Circumference Difference | Speedometer Error |
|---|---|---|---|---|
| 120/70-17 | 120/80-17 | +25.4 mm | +79.8 mm | -3.2% |
| 180/55-17 | 190/50-17 | -10.2 mm | -32.0 mm | +1.3% |
| 110/80-18 | 100/90-18 | +5.1 mm | +16.0 mm | -0.6% |
| 150/70-16 | 160/60-16 | -20.3 mm | -63.8 mm | +2.6% |
| 130/90-16 | 140/90-16 | +10.2 mm | +32.0 mm | -1.5% |
| 90/90-21 | 100/90-21 | +10.2 mm | +32.0 mm | -1.5% |
| 150/80-16 | 160/70-16 | -15.2 mm | -47.8 mm | +1.9% |
| 120/60-17 | 130/60-17 | +10.2 mm | +32.0 mm | -1.5% |
| 140/80-17 | 150/70-17 | -12.7 mm | -39.9 mm | +2.1% |
| 100/90-19 | 110/80-19 | +11.4 mm | +35.8 mm | -1.7% |
Common Motorcycle Tire Sizes
| Motorcycle Type | Front Tire Size | Rear Tire Size |
|---|---|---|
| Sport | 120/70-17 | 180/55-17 |
| Cruiser | 100/90-19 | 150/80-16 |
| Adventure | 90/90-21 | 150/70-17 |
| Touring | 120/70-18 | 180/55-17 |
| Dirt Bike | 80/100-21 | 110/100-18 |
| Cafe Racer | 100/90-18 | 130/80-17 |
| Chopper | 120/70-21 | 150/70-18 |
| Scooter | 120/70-12 | 130/70-12 |
| Enduro | 90/90-19 | 140/80-18 |
| Dual-Sport | 110/80-19 | 140/80-17 |
| Track Bike | 120/60-17 | 190/50-17 |
| Electric Motorcycle | 120/70-14 | 150/70-14 |
Motorcycle Tire Size Conversion Formula
The conversion formula for motorcycle tires involves several key measurements:
- Tire Width: Measured in millimeters
- Aspect Ratio: Height of the sidewall as a percentage of width
- Rim Diameter: Typically measured in inches
To calculate the overall tire diameter:
Overall Diameter = (2 × Tire Width × Aspect Ratio ÷ 100) + (Rim Diameter × 25.4)For a 180/55-17 tire:
- Tire Width: 180 mm
- Aspect Ratio: 55%
- Rim Diameter: 17 inches
Overall Diameter = (2 × 180 × 55 ÷ 100) + (17 × 25.4)
= 198 + 431.8
= 629.8 mmHow to find motorcycle tire size?
- Locate the tire sidewall: The size is molded into the rubber.
- Identify the code: Look for a series of numbers and letters, e.g., 180/55ZR17.
- Decode the information:
- 180: Tire width in millimeters
- 55: Aspect ratio
- ZR: Speed rating and radial construction
- 17: Rim diameter in inches
A tire marked 160/60R18 translates to:
- Width: 160 mm
- Aspect Ratio: 60% of width
- Construction: Radial
- Rim Diameter: 18 inches
How wide is a 90 motorcycle tire?
A 90 motorcycle tire refers to a tire with a width of 90 millimeters (approximately 3.54 inches).
Consider a tire size of 90/90-18:
- 90 mm: Width
- 90%: Aspect ratio (height is 90% of 90 mm, which is 81 mm)
- 18 inches: Rim diameter
What is 3.00 in tire size?
The designation “3.00” in a motorcycle tire size typically refers to the tire width in inches. This older sizing system is still used for some classic or vintage motorcycles.
A tire size of 3.00-18 would indicate:
- Width: 3.00 inches (approximately 76.2 mm)
- Rim Diameter: 18 inches
To convert this to the metric system:
3.00 inches × 25.4 mm/inch = 76.2 mmSources / References
- Motorcycle Safety Foundation: https://www.msf-usa.org/
- RevZilla: https://www.revzilla.com/common-tread/how-to-read-motorcycle-tire-sizes
Related Tools:
