ATV Tire Size: The Complete Guide
How to read the numbers, where to find your size and pressure, and what changes when diameter changes.
Quick Answer
- An ATV tire size is height x width - rim diameter in inches: 25x10-12 is nominally 25 in tall, 10 in wide, for a 12 in rim.
- Measure the tire by reading the sidewall, or by measuring ground to top for height and across the tread for width. Published heights run a little off nominal: Maxxis lists 25x8-12 at 25.0 to 25.6 in.
- A metric marking such as 205/80R12 converts to 24.9 in tall and 8.1 in wide (calculated). Use the size your owner's manual specifies.
How to Read ATV Tire Sizes (The 3-Number Format)
Every ATV tire has three numbers stamped on its sidewall, and once you know what they mean, buying tires becomes a lot less confusing. The format looks like this: 25×10-12. You might also see it written as 25x10x12 or 25/10-12, which all mean the same thing.
| Position | In 25×10-12 | What it means | Use |
|---|---|---|---|
| 1st number | 25 | Overall tire diameter (inches) | Used in the calculated diameter, circumference and speedometer figures |
| 2nd number | 10 | Tire width (inches) | Section width as marked |
| 3rd number | 12 | Rim / wheel diameter (inches) | Must match the wheel |
Polaris lists different front and rear sizes for the same machine, for example 25×8-12 (front) and 25×10-12 (rear) on the Sportsman 570.
What the "R" Means
In a size such as 25×10R12 the R marks radial construction; a dash instead means bias construction. We have no official source comparing how they perform on an ATV.
What If the Size Looks Different? (Metric Format)
Occasionally you will find a metric size like 205/80R12 on imported machines. In metric: 205 = width in mm, 80 = aspect ratio (sidewall as % of width), R = radial, 12 = rim diameter in inches. Use the size specified for your vehicle in the owner's manual.
ATV Tire Measurements: Nominal vs Published
The first number is nominal. Measured overall diameter and width vary by model, as the ranges below from the Maxxis 2023 US ATV/UTV catalog show. Revs per mile are calculated from the nominal diameter.
| Size | Nominal height in | Published height in | Published width in | Rim width in | Ply rating | Pressure listed psi | Max load lb | Revs per mile |
|---|---|---|---|---|---|---|---|---|
| 25x8-12 | 25 | 25.0 to 25.6 | 7.6 to 8.4 | 6.0 to 7.0 | 6, 8 | 7 to 18 | 342 to 805 | 807 |
| 25x10-12 | 25 | 25.0 to 25.6 | 9.4 to 10.6 | 7.0 to 8.0 | 6, 8 | 7 to 18 | 419 to 992 | 807 |
| 26x9-12 | 26 | 26.0 to 26.6 | 8.6 to 9.0 | 7.0 | 6, 8 | 7 to 18 | 397 to 827 | 776 |
| 26x11-12 | 26 | 26.0 to 26.6 | 10.4 to 11.2 | 8.0 | 6, 8 | 7 to 18 | 481 to 992 | 776 |
| 27x9-14 | 27 | 27.0 to 27.4 | 8.1 to 8.7 | 6.5 to 7.0 | 6, 8 | 17 to 18 | 419 to 847 | 747 |
| 27x11-12 | 27 | 27.0 to 27.6 | 10.4 to 11.3 | 7.5 to 8.0 | 6 | 7 to 24 | 494 to 992 | 747 |
| 28x10-14 | 28 | 28.0 to 28.7 | 9.3 to 10.4 | 7.0 to 8.0 | 8 | 18 | 480 to 992 | 720 |
| 29x11-14 | 29 | 29.4 to 29.5 | 10.6 to 11.1 | 8.0 | 6, 8 | 16 to 36 | 551 to 785 | 695 |
Pressure and load are as listed in the Maxxis size tables across its models; use the figures for your own tire and ATV. The full chart for more sizes is on the ATV tire size chart.
What Changing Tire Size Actually Does to Your ATV
Going Taller
Every 2 inches of added diameter adds 1 inch to the tire radius, so the axle sits about 1 inch higher (calculated). Polaris says to always use the size and type of tires specified for your vehicle and warns that non-standard tires affect handling and could cause an accident.
Going Wider
We have no official source for the effect of a wider tire on an ATV. Use the tire width specified in your owner's manual.
The Speedometer Error Nobody Talks About
Your ATV's speedometer counts wheel rotations calibrated to your stock tire size. A bigger tire covers more ground per rotation, so the speedo reads lower than your actual speed. The formula:
Example: You swapped from 25-inch to 28-inch tires, speedo shows 30 mph. Your actual speed is (28 ÷ 25) × 30 = 33.6 mph. That 3.6 mph gap is the calculated offset. Use our calculator for your sizes.
Tread, Terrain and Ply Rating
We have no official source for matching ATV tread patterns, tread depths or ply ratings to terrain, so this guide does not give recommendations. Use the tire type specified in your owner's manual: Polaris says to always use original equipment size and type when replacing tires.
Before Changing Tire Size
- Use the specified size. Polaris says to always use the size and type of tires specified for your vehicle and to refer to the Specifications chapter for tire type, size and pressure.
- Recalculate the speedometer offset. Use the formula or our calculator.
- Ask a dealer about other sizes. We have no official source for clearance, axle angle or lift requirements.
- Set the specified pressure. Polaris lists 7 psi (48.3 kPa) front and rear for the Sportsman 570; use the figure in your own manual and on the vehicle label.
ATV Tire Pressure
Use the cold tire pressure in your ATV's owner's manual or on the vehicle's tire label. We have no official source for a general ATV pressure range, so the pressure depends on your ATV and tire.
Never exceed the maximum pressure on the tire sidewall.
Tire Sizes and Pressures from Polaris Manuals
Examples from Polaris owner's manuals. Other brands publish their own figures in their manuals.
| Model | Front | Rear | Pressure |
|---|---|---|---|
| 2025 Sportsman 570 | 25x8-12 | 25x10-12 | 7 psi (48.3 kPa) front and rear |
| 2025 Sportsman 570 SP | 26x8-14 | 26x10-14 | 7 psi (48.3 kPa) front and rear |
| 2026 Ranger SP 570 (2-seat) | 25x8-12 | 25x10-12 | 10 psi (69 kPa) front and rear |
| 2026 Ranger Crew SP 570 | 25x8-12 | 25x10-12 | 16 psi (110 kPa) front and rear |
| 2023 RZR XP 1000 | 29x9-14 | 29x11-14 | See manual |
| 2024 General XP 1000 | 30x10x15 | 30x10x15 | See manual |
Tire Maintenance (Polaris Manual)
- Replace at 3 mm (1/8 in) tread depth: the Sportsman 570 manual says to always replace tires when tread depth is worn to 3 mm or less.
- Tires age: the manual says tires age even if unused, with cracks in the tread or sidewall rubber as evidence, and that old tires should be checked by tire specialists. The tire age and DOT code decoder reads the date.
- Check pressure and condition: the manual lists tire condition and pressure in its pre-ride inspection; see the PSI to kPa converter for units and the UTV tire guide for side-by-sides.
- Pavement: the manual says the vehicle's tires are primarily designed for off-road use.
Frequently Asked Questions
Try the ATV Tire Size Calculator
Enter any flotation size to get diameter, circumference, revs per mile, speedometer error, and ground clearance change vs stock.
Related Calculators
All tools and information provided on TireCalculatorHub are for informational purposes only. Always consult your vehicle's manufacturer manual and a qualified professional before making decisions about your vehicle's tires or modifications. TireCalculatorHub is not liable for any damages or issues arising from the use of information or tools on this website.