Tire Revolutions per Kilometer Calculator
See how many times a tire turns in one km. Use the calculator below. Results update as you type.
Revs per Km = 1,000,000 / (π × Diameter in mm)How the Tire Revolutions per Kilometer Calculator Works
This calculator works by dividing 1,000,000 millimeters (one kilometer) by the tire's circumference in millimeters. The answer is the number of wheel turns in one kilometer (0.621 miles).
- Enter the size code, for example 205/60R16.
- Read the diameter: 652.4 mm (25.69 in).
- Read the circumference: 2.050 m (80.70 in).
- Read the revolutions per kilometer: 487.9.
The tool is the metric partner of the revs per mile calculator. Multiply revs per km by 1.609 to get revs per mile.
The Formula
The formula is Revs per km = 1,000,000 ÷ (π × Diameter in mm).
Revs per km = 1,000,000 ÷ (π × Diameter (mm)) Revs per km = 318,310 ÷ Diameter (mm) Revs per Mile = Revs per km × 1.609344Worked example for a 700 mm (27.56 in) tire: 318,310 ÷ 700 = 454.7 revs per km, or 731.8 revs per mile.
Conversion Table
The conversion table lists diameter, circumference, revs per km and revs per 100 km for 12 sizes. Values run from 558 revs per km for a 165/65R14 to 398 revs per km for a 285/60R18.
The 100 km column matches the distance unit used for fuel consumption (liters per 100 km), which helps when checking trip computer data.
| Tire Size | Diameter (mm) | Circumference (m) | Revs / km | Revs / 100 km |
|---|---|---|---|---|
| 165/65R14 | 570 | 1.791 | 558.3 | 55,834 |
| 185/65R15 | 622 | 1.952 | 512.2 | 51,216 |
| 195/55R16 | 621 | 1.951 | 512.7 | 51,266 |
| 205/60R16 | 652 | 2.050 | 487.9 | 48,791 |
| 215/50R17 | 647 | 2.032 | 492.1 | 49,213 |
| 225/55R17 | 679 | 2.134 | 468.6 | 46,859 |
| 235/50R18 | 692 | 2.175 | 459.9 | 45,985 |
| 245/45R19 | 703 | 2.209 | 452.7 | 45,272 |
| 255/50R19 | 738 | 2.317 | 431.5 | 43,155 |
| 265/60R18 | 775 | 2.435 | 410.6 | 41,062 |
| 275/45R21 | 781 | 2.453 | 407.6 | 40,762 |
| 285/60R18 | 799 | 2.511 | 398.3 | 39,829 |
What Is the Tire Revolutions per Kilometer Calculator?
The Tire Revolutions per Kilometer Calculator is a tool that converts a tire size into the number of wheel turns per kilometer. European, Asian and Australian vehicle data sheets list rolling size in revs per km or in rolling circumference.
ECE R30 and R54 tire regulations, the European standards for passenger and commercial tires, use metric units, and digital tachographs in the European Union (EU) are set with a wheel-circumference constant derived from the same figure.
Common Uses
This calculator has 4 uses: tachograph setup, metric speedometer checks, rally and motorsport timing, and fuel log correction.
- Set up tachographs: Find the turns per km for the fitted tire.
- Check metric speedometers: Compare km/h readings across two sizes.
- Time rally stages: Calibrate trip meters that count wheel pulses.
- Correct fuel logs: Fix liters per 100 km figures after a size change.