What 235/70R16 Means on a Tire

It indicates a tire that is 235 millimeters wide, has a sidewall height that’s 70% of that width, uses radial construction, and fits a 16-inch wheel; in practical terms, it’s roughly 29 inches in overall diameter. This alphanumeric code is a standardized size designation you’ll find on the sidewall, and it directly affects fitment, ride, handling, speedometer accuracy, and load capability when paired with the correct load index and speed rating.

Breaking Down 235/70R16

The following points explain each part of the size marking so you can interpret what it means for the tire’s dimensions and construction.

• 235: The nominal section width in millimeters (approx. 9.25 inches) measured at the widest point of the mounted, inflated tire, not the tread only.
• 70: The aspect ratio, meaning the sidewall height is 70% of the tire’s width. Here, 0.70 × 235 mm = 164.5 mm.
• R: Radial construction, the industry-standard build in which the cords run radially across the tire.
• 16: The wheel (rim) diameter the tire fits, measured in inches.

Together, these elements define not just what wheel the tire fits, but also how tall the sidewall is and how the tire will generally behave on the road compared with other sizes.

Key Dimensions and Conversions

Here are the most relevant measurements derived from 235/70R16, including metric-to-imperial conversions drivers often look for.

• Section width: 235 mm ≈ 9.25 in
• Sidewall height: 164.5 mm ≈ 6.48 in
• Wheel diameter: 16 in (406.4 mm)
• Overall diameter: ≈ 735 mm ≈ 28.95 in
• Circumference: ≈ 2,319 mm ≈ 90.9 in
• Revolutions per mile: ≈ 697
• Typical approved rim width range: 6.0–8.0 in (7.0 in common “measuring rim”)

These figures are approximations; actual dimensions can vary slightly by brand and tread design, which is why manufacturers publish measured specs for each model.

What It Means for Fit and Performance

Changing tire size alters how your vehicle behaves and whether the tire physically fits your wheel wells and suspension. Here’s what this size implies.

• Handling and grip: A 235 mm width offers a moderate contact patch common on small-to-midsize SUVs and crossovers, balancing traction and stability.
• Ride comfort: The 70-series sidewall provides more cushioning than lower-profile tires, typically improving ride comfort and impact absorption.
• Speedometer/odometer: Overall diameter (~29 in) influences readings; a different diameter than stock can cause under- or over-reporting of speed and distance.
• Fuel economy: Wider or heavier tires can slightly reduce efficiency due to rolling resistance and aero drag.
• Load/towing: Capacity depends on the tire’s load index (e.g., 104, 107). Size alone doesn’t define how much the tire can carry.
• All-weather use: Sidewall height and tread design matter for snow and hydroplaning resistance; look for M+S or 3PMSF markings for winter capability.

If you deviate from your vehicle’s stock size, consult a fitment guide or professional to confirm clearance at full lock and compression, and to keep overall diameter within a safe range for driveline and brake systems.

Related Markings You Might Also See

Beyond the size code, other sidewall markings are critical to safety, performance, and legal compliance.

• Load index and speed rating: A pair like “109T” indicates maximum load per tire and the top sustained speed rating.
• Service type: P-metric (P235/70R16) for passenger applications; LT (LT235/70R16) for light-truck duties with different load/pressure standards.
• Load range/ply rating: SL/XL for passenger; C/D/E for LT, affecting allowable pressure and load capacity.
• Seasonal markings: M+S and Three-Peak Mountain Snowflake (3PMSF) denote winter traction standards.
• DOT code: Includes the plant and a four-digit date code (e.g., 0523 = 5th week of 2023).
• UTQG: Treadwear, traction, and temperature grades for passenger tires (not applicable to all LT tires).
• Max pressure and rotation/sidewall directions: Important for correct mounting and inflation.

These markings ensure you match the tire to your vehicle’s requirements and driving conditions, not just its wheel size.

Size Alternatives With Similar Diameter (Verify Before Switching)

If you’re considering a different size, keeping overall diameter within about ±3% of stock helps maintain proper clearances and accurate instrumentation.

• 235/65R17: ≈ 29.0 in diameter; “plus-one” option for 17-inch wheels with very similar height.
• 225/75R16: ≈ 29.3 in; slightly taller and narrower, often acceptable if clearance allows.
• 255/65R16: ≈ 29.1 in; a bit wider with a near-identical diameter.
• 245/65R16: ≈ 28.5 in; slightly shorter and wider, within typical tolerance.
• 225/70R16: ≈ 28.4 in; narrower and about 2% shorter, commonly used where extra clearance is needed.
• 215/75R16: ≈ 28.7 in; narrower with a similar overall height.

Always confirm wheel width compatibility, brake/suspension clearance, and the correct load index and speed rating for your vehicle and use case.

Where You’ll Typically See 235/70R16

This size is common on compact-to-midsize SUVs, crossovers, light-duty pickups, and some vans. It’s a versatile, comfort-oriented profile that balances ride quality and durability for everyday driving and light off-road use when paired with the right tread pattern.

Summary

235/70R16 specifies a tire that is 235 mm wide, with a 70% aspect ratio, radial construction, and a 16-inch wheel fitment, yielding an overall diameter of about 29 inches. Understanding this code—and related markings like load index and speed rating—helps you choose tires that fit correctly, preserve vehicle dynamics, and meet your hauling and weather needs.

What does R16 mean on a tire?

On a tire’s sidewall, the “R16” indicates that the tire has a radial construction and fits a 16-inch diameter rim. The “R” signifies radial construction, where internal cord plies run radially across the tire from one bead to the other, and the “16” specifies the diameter of the wheel the tire is designed to fit. 
Here’s a breakdown of what each part of “R16” means within a typical tire size code like 215/65R16:

• R: The “R” stands for Radial construction. Most modern tires are radial, meaning the internal plies are arranged radially across the tire, perpendicular to the direction of rotation. 
• 16: This number indicates the diameter of the wheel rim in inches. The tire is designed to mount onto a 16-inch rim. 

For example, in a 215/65R16 tire: 

• 215: The tire’s width in millimeters.
• 65: The aspect ratio, meaning the sidewall’s height is 65% of the tire’s width.
• R: It’s a radial tire.
• 16: It fits a 16-inch diameter wheel.

Is a 275 tire the same as a 33 inch tire?

No, a “275 tire” is not a 33-inch tire, but a specific tire size like a 275/60R20 or a 275/70R18 may have an overall diameter around 33 inches, depending on its profile and wheel size. A 33-inch tire refers to its approximate total diameter, whereas “275” in a metric tire size refers to the tire’s width in millimeters. 
Understanding Metric Tire Sizing

• 275 (Width): The “275” in a tire size like 275/60R20 is the tire’s width in millimeters. 
• 60 or 70 (Aspect Ratio): This number is the tire’s aspect ratio, representing the sidewall height as a percentage of the tire’s width. 
• R (Radial): This indicates the tire’s construction. 
• 20 or 18 (Wheel Diameter): This is the diameter of the wheel, in inches, that the tire is designed to fit. 

Why 275 is Not Necessarily 33
A tire labeled “33” refers to its overall diameter. For example: 

• A 275/60R20 tire has a total diameter of approximately 33 inches, making it close to a 33-inch tire. 
• A 275/70R18 tire has a total diameter of approximately 32.7 inches. 
• Other tire widths, like 305/70R16, can also approximate 33 inches. 

To find the exact diameter, you must consider the entire tire size code.

What does 235-70 R16 mean?

The “235/70R16” on a tire means its width is 235 millimeters, its sidewall height is 70% of that width, it is a radial-constructed tire (indicated by “R”), and it fits a 16-inch diameter wheel rim.
 
Here is a breakdown of each part of the tire size:

• 235: This is the tire’s section width in millimeters, measured from the outermost point of its sidewall on one side to the outermost point on the other. 
• 70: This is the aspect ratio, which represents the height of the tire’s sidewall as a percentage of its width. So, the sidewall height is 70% of the 235mm width. 
• R: This letter signifies that the tire has a radial construction. This is the most common internal construction for tires today, offering benefits like a smoother ride and longer tread life. 
• 16: This number indicates the rim diameter in inches, specifying the size of the wheel the tire is designed to mount onto. 

Is a 235 the same as a 31 inch tire?

No, a “235” tire is not the same as a 31-inch tire because “235” is a metric tire size (235/75R15) where the “235” represents the width in millimeters, while a “31-inch” tire (31×10.50R15) is a flotation or standard tire size where “31” represents the overall diameter in inches. A 235/75R15 tire is typically around 29 inches in diameter, whereas a 31-inch tire is, as the name suggests, about 31 inches in diameter.
 
Understanding Tire Sizes

• Metric (235/75R15):
  • 235: The tire’s width in millimeters. 
  • 75: The aspect ratio, which is the tire’s sidewall height as a percentage of its width. 
  • R: Indicates the tire’s construction (Radial). 
  • 15: The diameter of the wheel the tire fits, in inches. 
• Standard/Flotation (31×10.50R15):
  • 31: The tire’s approximate overall diameter in inches. 
  • 10.50: The tire’s approximate width in inches. 
  • R: Indicates the tire’s construction (Radial). 
  • 15: The diameter of the wheel the tire fits, in inches. 

Key Differences

• Diameter: A 31-inch tire has a significantly larger overall diameter than a typical 235/75R15 tire. 
• Width: A 31×10.50R15 tire is also wider (approximately 10.5 inches) than a 235/75R15 tire (approximately 9.3 inches). 
• Interchangeability: Due to these differences in diameter and width, they are not interchangeable and offer different performance characteristics.