Tire Size Calculator
Calculate tire dimensions from the tire code (e.g., 205/55R16 or 90/90-17). Get sidewall height, overall diameter, circumference, and revolutions per km. Compare two tire sizes and see the speedometer correction.
Enter a tire code in the format 205/55R16 or 90/90-17
Common Tire Sizes
| Tire Code | Common Vehicle | Overall Diameter |
|---|---|---|
| 155/80R13 | Maruti 800 / Tata Nano | 578.2 mm |
| 165/65R14 | Maruti Alto 800 / Swift (old) | 570.1 mm |
| 185/65R15 | Hyundai i20 / Maruti Swift | 621.5 mm |
| 195/65R15 | Honda City / Maruti Ciaz | 634.5 mm |
| 205/55R16 | Honda City VX / Hyundai Elantra | 631.9 mm |
| 225/45R17 | Toyota Innova Crysta / Creta | 634.3 mm |
| 90/90-17 | Hero Splendor / Honda Shine (2W) | 593.8 mm |
| 100/80-17 | TVS Apache / Honda CB Unicorn (2W) | 591.8 mm |
| 120/80-17 | Royal Enfield Classic 350 rear (2W) | 623.8 mm |
| 110/80-19 | Royal Enfield Himalayan front (2W) | 658.6 mm |
Frequently Asked Questions
A tire code like 205/55R16 has three parts: 205 is the section width in mm, 55 is the aspect ratio (sidewall height as a % of width), and 16 is the rim diameter in inches. For Indian two-wheelers, the format is often 90/90-17 or 100/80-17, where the dash replaces the "R" and the numbers have the same meaning.
Overall Diameter = (Rim Diameter × 25.4) + (2 × Sidewall Height). Sidewall Height = Width × (Aspect Ratio / 100). For 205/55R16: sidewall = 205 × 0.55 = 112.75 mm; diameter = (16 × 25.4) + (2 × 112.75) = 406.4 + 225.5 = 631.9 mm. For 90/90-17: sidewall = 90 × 0.90 = 81 mm; diameter = (17 × 25.4) + 162 = 593.8 mm.
A larger tire covers more ground per revolution, so your actual speed is higher than what the speedometer shows — it reads LOW. A smaller replacement tire does the opposite: the speedo reads HIGH. The correction percentage is (New Diameter − Original Diameter) / Original Diameter × 100. Even a 3% difference can accumulate into speeding tickets on a long drive.
Common Indian motorcycle sizes: Hero Splendor / Honda Shine use 80/100-18 (front) and 80/100-18 (rear); Royal Enfield Classic 350 uses 90/90-19 (front) and 120/80-18 (rear); TVS Apache RTR 160 uses 90/90-17 and 100/80-17. Popular Indian car sizes: Maruti Suzuki Swift and Baleno use 185/65R15; Hyundai Creta uses 205/60R16 or 215/60R17; Tata Nexon uses 195/60R16.