A 285/70R17 tire is a popular truck and SUV size because it lands close to the 33-inch class without being as wide as many 33×12.50 tires. By tire-size math, it has a nominal diameter of about 32.7 inches, a 285 mm section width, and a 7.85-inch sidewall. Real-world measurements can vary by tire model, load range, and measuring rim, so use these numbers as a fitment baseline—not a guarantee.
Quick Answer
A 285/70R17 tire calculates to about 32.71 inches tall, 11.22 inches wide, and 7.85 inches of sidewall on a 17-inch wheel. It is often called a “33-inch class” tire, but it is slightly shorter than a true 33-inch tire by nominal math.
Key Takeaways
- A 285/70R17 tire has a calculated nominal diameter of 32.71 inches, or 830.8 mm.
- The nominal section width is 285 mm, which equals about 11.22 inches.
- The sidewall height is 199.5 mm, or about 7.85 inches.
- It fits a 17-inch wheel, but the safe rim-width range depends on the exact tire model.
- Speedometer error depends on the tire size your vehicle was calibrated for, not on 285/70R17 alone.
What Is a 285/70R17 Tire?
A 285/70R17 tire is a metric radial tire size commonly used on trucks, SUVs, and off-road builds. The size code tells you four important details:
- 285 is the nominal section width in millimeters.
- 70 is the aspect ratio, meaning the sidewall height is 70% of the tire width.
- R means radial construction.
- 17 means the tire fits a 17-inch wheel diameter.
That sizing system matches how major tire makers and industry groups explain tire sidewall markings: width is listed in millimeters, aspect ratio is a percentage of width, and rim diameter is listed in inches. For replacement tires, also check the load index, speed rating, and load range because the same 285/70R17 size can be sold in different constructions.
285/70R17 Size at a Glance
| Specification | Value |
| Nominal section width | 285 mm / 11.22 in |
| Aspect ratio | 70% |
| Sidewall height | 199.5 mm / 7.85 in |
| Wheel diameter | 17 in |
| Calculated overall diameter | 830.8 mm / 32.71 in |
| Tire class | Near-33-inch / 33-inch class |
How Tall Is a 285/70R17 Tire?
A 285/70R17 tire is about 32.71 inches tall by nominal tire-size calculation. In metric, that is about 830.8 mm. This puts it just under a true 33-inch tire.
Sidewall Height Calculation
The sidewall height is calculated from the width and aspect ratio:
285 mm × 0.70 = 199.5 mm
Convert that to inches:
199.5 mm ÷ 25.4 = 7.85 inches
Overall Diameter Calculation
To get overall tire diameter, double the sidewall height and add the wheel diameter:
(7.85 × 2) + 17 = 32.71 inches
That number is useful for comparing sizes, but it is still a calculated nominal dimension. A real tire may measure slightly taller or shorter after inflation, tread design, load range, and manufacturer measuring standards are considered.
Note: Published overall diameter and revolutions per mile can vary by tire model. Always check the exact tire’s specification sheet before buying wheels, trimming fenders, or recalibrating your speedometer.
285/70R17 Width and Sidewall Height
A 285/70R17 tire has a nominal section width of 285 mm, which equals about 11.22 inches. The sidewall height is 199.5 mm, or about 7.85 inches.
Section width is not always the same as tread width. Section width measures the tire from sidewall to sidewall on a specified measuring rim. Tread width is the part of the tire that contacts the road, and it can be narrower than the section width depending on the tire model.
Is 285/70R17 the Same as a 33-Inch Tire?
A 285/70R17 is close to a 33-inch tire, but it is not exactly the same by calculation. It is about 32.71 inches tall, so it is roughly 0.29 inch shorter than a true 33-inch tire.
| Size | Nominal / Calculated Height | Width |
| 285/70R17 | 32.71 in | 11.22 in nominal section width |
| 33×12.50R17 | 33 in nominal | 12.50 in nominal section width |
| 33×10.50R17 | 33 in nominal | 10.50 in nominal section width |
The biggest practical difference is width. A 33×12.50R17 is usually much wider than a 285/70R17, so it can create more rubbing at the upper control arm, fender liner, mud flap, or outer fender.
Will 285/70R17 Fit on 17-Inch Wheels?
Yes, a 285/70R17 tire is designed for a 17-inch wheel diameter. The 17-inch part is not flexible; the tire bead must match the wheel diameter.
The other key fitment point is wheel width. Many 285/70R17 tires use an approved rim-width range around 7.5 to 9.5 inches, but this is not universal. Some tire models may specify a narrower or wider range. Check the exact tire manufacturer’s spec sheet before mounting.
Warning: Do not choose a tire by diameter alone. Confirm wheel diameter, approved rim width, load index, speed rating, load range, and vehicle clearance. A tire that mounts on the wheel can still be unsafe or rub badly on the vehicle.
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Load Range, LT vs P-Metric, and Vehicle Placard Checks
Not every 285/70R17 tire is built the same. You may see P285/70R17, LT285/70R17, or different service descriptions and load ranges such as C, D, or E. LT tires are commonly used on trucks and may carry more load at higher inflation pressures, but they can also ride stiffer and weigh more.
Before replacing tires, check the vehicle tire placard and owner’s manual for the recommended tire size, load rating, and inflation pressure. The maximum pressure molded on the tire sidewall is not automatically the correct daily driving pressure for your vehicle.
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Will 285/70R17 Rub or Need Modifications?
A 285/70R17 sits near the upper limit of many stock truck and SUV wheel wells. Some vehicles clear this size with no changes, while others need trimming, different wheel offset, a leveling kit, or suspension changes.
Common Rub Points
Rubbing is most common at:
- Front fender liner
- Mud flap or splash guard
- Body mount area on some trucks
- Upper control arm
- Sway bar
- Outer fender edge during compression
Rubbing may happen only at full steering lock, under braking, when reversing, or when the suspension compresses off-road.
Fitment Variables That Matter
Two vehicles with the same tire size can fit differently because of wheel offset, backspacing, suspension height, alignment settings, tire shoulder shape, tread design, and fender liner shape. A 285/70R17 all-terrain with square shoulders may rub where a round-shouldered highway tire does not.
Pro Tip: Test clearance at full left lock, full right lock, and while the suspension is compressed. Static parking-lot clearance is not enough to prove trail or highway clearance.
How Does 285/70R17 Affect the Speedometer?
A larger tire travels farther with each rotation. If your vehicle was calibrated for a smaller factory tire, switching to 285/70R17 can make the speedometer read lower than your actual road speed. The exact error depends on the original tire diameter.
Use this formula:
Actual speed = indicated speed × new tire diameter ÷ original tire diameter
| Original Tire Size | Original Diameter | Actual Speed When Speedometer Shows 60 mph |
| 275/70R17 | 32.16 in | About 61.0 mph |
| 265/70R17 | 31.61 in | About 62.1 mph |
| 245/70R17 | 30.50 in | About 64.3 mph |
The odometer can also log fewer miles than you actually drive. Large tire-diameter changes may also affect ABS, traction control, stability control, transmission shift behavior, and driver-assistance systems because those systems use wheel-speed data.
Best Equivalent Sizes for 285/70R17
The closest alternatives depend on whether you want the same wheel diameter, more width, more height, or less rubbing. These sizes are common comparison points:
| Size | Calculated / Nominal Diameter | Best For |
| 285/70R17 | 32.71 in | Baseline size |
| 33×10.50R17 | 33 in nominal | Near-33 height with narrower width |
| 33×12.50R17 | 33 in nominal | Wider stance and more aggressive look |
| 305/65R17 | 32.61 in | Similar height, wider footprint |
| 295/70R17 | 33.26 in | Slightly taller and wider |
| 275/70R17 | 32.16 in | Slightly shorter and narrower |
| 255/80R17 | 33.06 in | Tall, narrow fitment |
Do not assume a listed equivalent will fit your vehicle. Width, wheel offset, load rating, and shoulder shape can matter as much as diameter.
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285/70R17 Clearance Issues to Know
A 285/70R17 tire can add height and width compared with many factory truck sizes. That can improve ground clearance, but it can also reduce space around suspension and body components.
Before buying, check:
- Fender liner clearance at full steering lock
- Upper control arm clearance with your chosen wheel offset
- Body mount and mud flap clearance on trucks known for rubbing
- Suspension compression clearance for off-road use
- Spare tire storage, especially under-bed spare locations
- Speedometer calibration after installation
When a 285/70R17 Tire Makes Sense
A 285/70R17 makes sense when you want a near-33-inch tire with moderate width. It can be a strong choice for trucks and SUVs that need more ground clearance, more sidewall, and better off-road capability without jumping to a very wide 12.50-inch tire.
This size is especially popular when:
- You want a taller tire on a 17-inch wheel.
- You want more sidewall for rough roads and trails.
- You prefer a narrower tire than 33×12.50R17.
- Your vehicle can clear the added height and width.
- You are willing to verify speedometer and fitment changes.
It may not be the best choice if you want factory ride quality, maximum fuel economy, no chance of rubbing, or a tire that fits without any measurement or test fitting.
The safest way to choose 285/70R17 tires is to treat the calculated size as a starting point, then confirm the exact tire model’s measured specs, load rating, approved rim width, and vehicle clearance.
Frequently Asked Questions
What is the actual height of a 285/70R17 tire?
The calculated nominal height of a 285/70R17 tire is about 32.71 inches, or 830.8 mm. Actual measured height can vary slightly by tire brand, tread depth, load range, inflation, and measuring rim.
Are 285/70R17 tires the same as 33-inch tires?
They are close, but not exactly the same. A 285/70R17 calculates to about 32.71 inches tall, so it is roughly 0.29 inch shorter than a true 33-inch tire. Many people still call it a 33-inch class tire.
How much taller is a 35-inch tire than a 285/70R17?
A nominal 35-inch tire is about 2.29 inches taller than a 285/70R17. On a 17-inch wheel, a 35-inch tire has about 9 inches of sidewall by nominal math, compared with about 7.85 inches for a 285/70R17.
What is a 285/70R17 equivalent to?
A 285/70R17 is equivalent to a near-33-inch tire. Common comparison sizes include 33×10.50R17, 33×12.50R17, 305/65R17, 295/70R17, 275/70R17, and 255/80R17. None are perfect swaps for every vehicle, so compare diameter, width, load rating, and wheel requirements.
Will 285/70R17 tires fit stock suspension?
Sometimes. Fitment depends on the vehicle, wheel offset, wheel width, alignment, tire model, and suspension travel. Some stock trucks clear 285/70R17 tires; others rub at full lock or compression and need trimming, offset changes, or a leveling kit.
Do 285/70R17 tires affect speedometer accuracy?
They can. If 285/70R17 is larger than your original tire size, your actual speed may be higher than the speedometer shows. The exact difference depends on the original tire diameter, so calculate the percentage change before installing.
Conclusion
A 285/70R17 tire gives you a calculated diameter of about 32.71 inches, a nominal width of 11.22 inches, and a sidewall height of about 7.85 inches. It is a strong near-33-inch option for many trucks and SUVs, but it is not a one-size-fits-all upgrade. Check the exact tire’s spec sheet, confirm approved rim width, match the required load rating, test vehicle clearance, and account for speedometer changes before you buy.
Sources
- Michelin: Tire Markings Explained — supports tire width, aspect ratio, construction, rim diameter, load, speed, and pressure-label interpretation.
- Tire Industry Association: Reading a Tire Sidewall — supports sidewall code definitions and aspect-ratio meaning.
- U.S. Tire Manufacturers Association: Tire Care and Safety Guide — supports proper tire size, type, load capacity, inflation, and tire safety checks.
- NHTSA TireWise — supports tire safety awareness and tire-rating context.
- Tire Rack: Speedometer Accuracy — supports how tire diameter changes affect speedometer readings.
- Tire Rack: Plus Size Wheels and Tires — supports diameter-change effects on speedometer, ABS, traction control, and stability systems.
