Tire Size Comparison Tools

Popular Tire Sizes Quick Reference

Looking for common tire sizes? This table shows popular tire dimensions for passenger cars, SUVs, and trucks. Use these as a starting point when comparing sizes in our calculator above.

💡 Tip: Enter any of these sizes in our calculator above to see how they compare to your current tires or to explore upgrade options. Remember to stay within 3% of your original tire diameter for safe operation.

How to Use the Tire Size Comparison Calculator

Our free tire size calculator helps you compare different tire sizes and understand exactly how changes will affect your vehicle's performance, speedometer accuracy, and overall handling. Whether you're upgrading to larger wheels, switching to performance tires, or replacing worn tires, this tool ensures you make informed decisions.

Understanding Tire Size Numbers

Tire sizes follow a standardized format that looks like this: 225/50R17. Here's what each number means:

• Width (225): The first number is the tire's width in millimeters, measured from sidewall to sidewall. A wider tire (like 245mm) provides more contact with the road, improving grip but potentially reducing fuel efficiency.
• Aspect Ratio (50): This percentage represents the tire's sidewall height as a percentage of its width. In this example, the sidewall is 50% of 225mm = 112.5mm tall. Lower aspect ratios (like 40 or 45) create a sportier look and sharper handling, while higher ratios (60-70) provide a more comfortable ride.
• Construction (R): The letter "R" stands for Radial construction, which is the standard for modern tires. You may occasionally see "D" for diagonal/bias-ply construction on older vehicles or trailers.
• Rim Diameter (17): This final number indicates the wheel diameter in inches that the tire is designed to fit. Common sizes range from 15" to 22" or larger for trucks and performance vehicles.

Step-by-Step Guide to Using the Calculator

1. Find Your Original Tire Size: Look at your current tire's sidewall for a number like "225/50R17", check your vehicle's door jamb sticker, or consult your owner's manual. This is your baseline for comparison.
2. Enter Original Specifications: Input the width (e.g., 225), aspect ratio (e.g., 50), and rim diameter (e.g., 17) into the "Original Tire" section of our calculator.
3. Input New Tire Size: Enter the specifications of the tire size you're considering. This could be an upgrade option, a different brand's equivalent, or a tire shop recommendation.
4. Review Instant Results: Our calculator immediately displays diameter differences, width changes, circumference variations, and speedometer impact. Look for the percentage difference - staying within ±3% is recommended.
5. Check Visual Comparison: Scroll down to see side-by-side visual representations showing how the new tire size compares to your original in both front and side views.
6. Verify Speedometer Accuracy: Note the "actual speed" reading. If it shows you'll be going 62 mph when your speedometer reads 60 mph, this 3.3% difference is acceptable. Larger differences may require recalibration.

Understanding Your Results

Why Diameter Matters

The overall diameter of your tire is crucial for vehicle performance. When you change tire diameter, you're changing:

• Speedometer Accuracy: A larger diameter tire travels farther per revolution, making your speedometer read slower than your actual speed. Conversely, a smaller tire makes it read faster. Most experts recommend staying within 3% of your original tire diameter.
• Gear Ratios: Larger tires effectively change your vehicle's gear ratios, potentially improving top speed but reducing acceleration and fuel economy.
• Ground Clearance: Increasing diameter raises your vehicle's ride height, which can be beneficial for off-roading but may affect handling on paved roads.
• ABS and Traction Control: Significant diameter changes can affect these safety systems' calibration, potentially compromising their effectiveness.

Width and Aspect Ratio Impact

Wider Tires: Increasing tire width provides more contact patch with the road, improving traction and cornering grip. However, wider tires also increase rolling resistance, potentially reducing fuel economy by 1-2 mpg. They may also cause rubbing issues if your wheel wells don't have adequate clearance.

Lower Aspect Ratio: Lower profile tires (lower aspect ratio) offer sharper steering response and better handling, making them popular for performance applications. The trade-off is a firmer ride, as there's less sidewall to absorb road imperfections. Lower profile tires are also more susceptible to wheel damage from potholes.

Expert Tips for Choosing Tire Sizes

Safety Considerations

• Stay within 3% diameter: This is the industry-standard safe range for tire size changes. Larger variations can cause issues with ABS, traction control, and speedometer accuracy.
• Maintain load rating: Never choose tires with a lower load rating than your original equipment. The load index is printed on your tire sidewall (e.g., 91, 95) and indicates maximum weight capacity.
• Check clearance: Before purchasing, ensure new tires won't rub against your vehicle's fenders, suspension components, or frame, especially when turning or hitting bumps.
• Consider seasonal needs: Narrower tires often perform better in snow and rain as they can cut through to the pavement. Wider tires excel in dry conditions and provide better grip for performance driving.

Performance Optimization

• For better handling: Consider plus-sizing (larger wheel, lower profile tire) while maintaining overall diameter. This reduces sidewall flex and improves steering response.
• For better comfort: Choose tires with higher aspect ratios (taller sidewalls). They absorb road imperfections better, providing a smoother ride.
• For off-roading: Larger diameter and narrower tires with taller sidewalls provide better ground clearance and flexibility for rough terrain.
• For fuel economy: Stick close to original tire dimensions and avoid significantly wider tires, which increase rolling resistance.

When to Replace Tires

• Tread depth: Replace tires when tread depth reaches 2/32" (the legal minimum in most states). Use the penny test: insert a penny into the tread with Lincoln's head upside down - if you can see all of his head, it's time for new tires.
• Age matters: Even if tread looks good, replace tires that are 6+ years old. Rubber degrades over time regardless of use. Check the DOT code on your tire sidewall for manufacture date.
• Uneven wear: If tires wear unevenly (inside, outside, or center), this indicates alignment, pressure, or suspension issues that should be addressed before installing new tires.
• Replace in sets: For best performance and safety, replace all four tires at once. If budget is limited, at minimum replace both tires on the same axle with identical models.

Common Tire Size Upgrades and Conversions

Planning to upgrade your wheels or tires? This chart shows popular plus-sizing options and equivalent tire sizes that maintain similar overall diameter. These conversions keep you within the safe 3% diameter tolerance while improving performance or aesthetics.

Popular Plus-Sizing Conversions

Width Equivalent Conversions (Same Diameter)

These conversions maintain the same overall diameter while changing tire width for different performance characteristics:

⚠️ Important: Always verify fitment with a tire professional before purchasing. These conversions are general guidelines - your specific vehicle may have different clearance limitations or require different offsets. Use our calculator above to compare any tire sizes and check the exact diameter differences.

🚗 Vehicle-Specific Tire Size Guides

Get detailed tire size information, OEM specifications, and upgrade options for your specific vehicle: