Which tire is taller: 70 or 75?

A 75-series tire is taller than a 70-series tire—if the section width and wheel diameter are the same—because the “75” denotes a higher aspect ratio (taller sidewall) than “70.” In tire sizing, that second number represents sidewall height as a percentage of the tire’s width, so all else equal, 75 yields a greater overall diameter than 70.

How tire sizing works

Modern tire sizes like 265/70R17 or 225/75R16 follow a standard format: width in millimeters, aspect ratio (the “70” or “75”), construction (R for radial), and wheel diameter in inches. The aspect ratio is the key to the height question: it’s the sidewall height expressed as a percentage of the width. A higher aspect ratio means a taller sidewall, which increases the overall tire height when the wheel size and width remain unchanged.

The core formula

The overall diameter is calculated by adding the wheel diameter to twice the sidewall height. Sidewall height equals section width times aspect ratio (converted from percent), then converted from millimeters to inches.

The following steps show how to compute overall diameter from a tire size:

• Convert sidewall height: sidewall = width_mm × (aspect_ratio/100).
• Convert millimeters to inches: sidewall_in = sidewall_mm ÷ 25.4.
• Overall diameter (inches) = wheel_diameter_in + 2 × sidewall_in.

Using this method lets you compare 70- vs 75-series sizes accurately and predict clearance, gearing, and speedometer effects.

Real-world comparisons

To illustrate the difference between 70 and 75 series tires, here are two common matchups where only the aspect ratio changes.

Example 1: 265/70R17 vs 265/75R17

Both tires are 265 mm wide on 17-inch wheels.

Key figures to note in this comparison:

• 265/70R17: sidewall = 265 × 0.70 = 185.5 mm (≈ 7.30 in); overall ≈ 31.61 in.
• 265/75R17: sidewall = 265 × 0.75 = 198.75 mm (≈ 7.83 in); overall ≈ 32.65 in.
• Difference: ≈ 1.05 inches taller (about 3.3%).

This shows how adding 5 aspect-ratio points raises the tire roughly an inch in overall diameter at this width.

Example 2: 225/70R16 vs 225/75R16

Both tires are 225 mm wide on 16-inch wheels.

Important results from this pairing:

• 225/70R16: sidewall ≈ 157.5 mm (≈ 6.20 in); overall ≈ 28.40 in.
• 225/75R16: sidewall ≈ 168.75 mm (≈ 6.64 in); overall ≈ 29.28 in.
• Difference: ≈ 0.88 inches taller (about 3.1%).

The increase is slightly smaller here because the tire is narrower, and the extra 5% is applied to a smaller width.

Why the difference matters

Switching from a 70 to a 75 series tire affects more than looks. A taller tire can change speedometer accuracy (it will read lower than actual speed), alter effective gearing (lower engine RPM at a given speed), and impact clearance in the wheel wells or against suspension components. It can also influence ride comfort and handling due to the taller sidewall’s added compliance.

Quick reference

If you’re deciding between 70 and 75 with the same width and wheel size, keep these practical points in mind:

• Height relationship: 75-series is taller than 70-series when width and rim size match.
• How much taller: roughly 2×(0.05 × width_mm) in millimeters, or about 0.8–1.1 inches for common widths (225–285 mm).
• Fitment check: verify fender and suspension clearance; a 3% diameter increase is typical when moving from 70 to 75.
• Instrumentation: expect a modest speedometer/odometer error unless recalibrated.
• Ride and handling: slightly softer ride, marginally slower steering response due to taller sidewall.

Thinking through these factors will help ensure the taller tire works with your vehicle without unexpected trade-offs.

Bottom line

Between “70” and “75,” the 75-series tire is taller—provided the section width and wheel diameter are the same—because the aspect ratio is higher, producing a taller sidewall and larger overall diameter.

Summary

A tire’s second number (70 or 75) is its aspect ratio: sidewall height as a percentage of width. With identical width and wheel diameter, a 75-series tire is taller than a 70-series tire, typically by about 3% in overall diameter. That added height can affect clearance, speedometer accuracy, gearing, and ride, so confirm fitment and performance implications before switching.

How tall is a 70 series tire?

A tire’s total height cannot be determined from just the “70” number because the “70” is the aspect ratio, which is 70% of the tire’s width, not its total height. To calculate the height, you need the tire’s full size designation, which includes its width and rim diameter, such as in a tire size like 225/70R15. For example, for a 225/70R15 tire, the sidewall height is 157.5 mm (225mm x 0.70), and the total tire height is 696 mm or approximately 27.4 inches (157.5 mm x 2 sidewalls + 381 mm rim diameter). 
Understanding Tire Size Numbers 

• Example: 225/70R15:
  • 225: This is the width of the tire in millimeters.
  • 70: This is the aspect ratio (or profile), which is the height of the sidewall as a percentage of the tire’s width. For a “70” aspect ratio, the sidewall height is 70% of the tire’s width.
  • R: This indicates that the tire has a radial construction.
  • 15: This is the diameter of the wheel rim that the tire is designed to mount on, in inches.

How to Calculate Total Height

1. Calculate Sidewall Height: Opens in new tabMultiply the tire’s width in millimeters by the aspect ratio (e.g., 225 mm * 0.70 = 157.5 mm). 
2. Convert Rim Diameter to Millimeters: Opens in new tabConvert the rim diameter to millimeters (e.g., 15 inches * 25.4 mm/inch = 381 mm). 
3. Add the Sidewalls and Rim: Opens in new tabAdd the height of the two sidewalls (sidewall height x 2) to the rim diameter (157.5 mm * 2 + 381 mm = 696 mm). 
4. Convert to Inches (Optional): Opens in new tabDivide the total millimeters by 25.4 to get the height in inches (696 mm / 25.4 ≈ 27.4 inches). 

How tall is a 75R tire?

Tire Size Calculator for 205-75R15 – Tire & Wheel Plus Sizing

	Imperial	Metric
Overall Diameter:	27.11 in	688.50 mm
Sidewall Height:	6.05 in	153.75 mm
Radius:	13.55 in	344.25 mm
Circumference:	85.16 in	2,162.99 mm

Which tire size is taller?

To find a taller tire size, look for tires with a larger overall diameter, which is achieved by increasing the wheel diameter, tire width, or aspect ratio (sidewall height). Common ways to increase tire height include choosing tires with a higher aspect ratio (the percentage following the slash in the tire size) or selecting a larger wheel diameter. Using taller tires can provide more ground clearance and a smoother ride but may also affect vehicle handling, speedometer accuracy, and the function of Advanced Driver Assistance Systems (ADAS). Always check your vehicle manufacturer’s guidelines and consider professional recalibration for your speedometer, as recommended by resources like Discount Tire and Tires Plus.
 
How Taller Tires Increase Height

• Increase Wheel Diameter: Opens in new tabA larger wheel diameter (the last set of numbers in the tire size) directly increases the tire’s overall height. 
• Increase Aspect Ratio: Opens in new tabThe aspect ratio is the two-digit number following the tire’s width (e.g., 65 in 215/65R16). A higher aspect ratio means a taller sidewall and, consequently, a taller overall tire. 
• Increase Tire Width: Opens in new tabA wider tire (the three-digit number before the slash) contributes to the overall height and can change handling. 

Considerations for Taller Tires

• Ground Clearance: Opens in new tabTaller tires provide more space between the vehicle and the road, which is beneficial for off-road driving. 
• Ride Quality: Opens in new tabLarger tires, especially with more sidewall, can absorb bumps and lead to a smoother ride. 
• Speedometer Accuracy: Opens in new tabTaller tires travel a greater distance per revolution, making your speedometer read slower than your actual speed. 
• Handling and Stability: Opens in new tabA higher center of gravity can alter a vehicle’s handling, potentially increasing body roll and decreasing stability during turns. 
• ADAS and Safety Systems: Opens in new tabChanges in tire size can impact the calibration of Advanced Driver Assistance Systems (ADAS), affecting their proper function. 
• Vehicle Fitment: Opens in new tabEnsure that taller tires will fit within your vehicle’s wheel wells and that the wheel size is appropriate for the rim. 

Before You Buy

1. Check Manufacturer Guidelines: Refer to your vehicle manufacturer’s recommendations for appropriate tire sizes. 
2. Use a Tire Size Calculator: A calculator can help determine how a different tire size will affect your vehicle’s overall diameter and other measurements. 
3. Consider Professional Help: Consult with tire professionals to ensure proper fitment, recalibrate your speedometer, and check for potential issues with safety systems. 

What is the difference between 70 and 75 tires?

The main difference is that a 75 aspect ratio tire has a taller sidewall than a 70 aspect ratio tire, as the number represents the sidewall height as a percentage of the tire’s width. A 75-series tire, for example, is taller and offers a more comfortable and aggressive look, with increased off-road capability and better shock absorption. However, a 75-series tire can also lead to a larger overall diameter, which may negatively affect fuel economy and require vehicle re-gearing, while a 70-series tire provides better handling performance and a larger selection of modern tire designs.
 
Aspect Ratio 

• 70 vs. 75: The “75” in a tire size like 265/75R16 represents a sidewall height that is 75% of the tire’s width (265mm). In the same example, a 70-series tire has a sidewall height that is 70% of its width.

Benefits of a 75-Series Tire (Taller Sidewall) 

• Ride Comfort: The taller sidewall provides more flexibility to absorb bumps, resulting in a more comfortable ride.
• Off-Road Performance: A taller sidewall improves off-road grip by maintaining better contact with the ground.
• Aggressive Look: Vehicles equipped with 75-series tires often have a more commanding and aggressive off-road appearance.

Considerations for a 75-Series Tire

• Overall Tire Diameter: A taller sidewall from a 75-series tire leads to a larger overall tire diameter and rolling circumference. 
• Vehicle Performance Impact:
  • Fuel Economy: Larger tires require more power to rotate, potentially increasing fuel consumption. 
  • Gear Ratios: The increased size can cause the speedometer to be inaccurate and may necessitate re-gearing the vehicle’s drivetrain for optimal performance. 
• Brake Clearance: The larger tire may require modifications to the brake caliper. 

Benefits of a 70-Series Tire (Shorter Sidewall) 

• Handling: Opens in new tabThe shorter sidewall offers better vehicle handling performance and stability.
• Tire Variety: Opens in new tab70-series tires were a modern standard for a long time, meaning they have a large selection of designs for highway and all-terrain use.

When to Choose Which

• 70-Series: A good choice for better on-road performance, a wider variety of tire options, and improved fuel economy. 
• 75-Series: Ideal for drivers seeking a more comfortable ride, enhanced off-road capabilities, and a more commanding, aggressive stance on their vehicle.