Meta Description: 325/60R20 tire measures 35.35 inches in diameter and 12.8 inches wide. Explore the tire size calculation, dimensions, formula, and chart.
Direct Answer: 325/60R20 in Inches
A 325/60R20 tire measures approximately 35.35 inches in overall diameter, 12.80 inches in width, and 20 inches in rim diameter.
The sidewall height is 325 × 0.60 ÷ 25.4 = 7.68 inches.
The overall diameter is 20 + (2 × 7.68) = 35.35 inches.
These measurements describe a tire’s nominal dimensions based on its size code. Actual measurements can vary slightly by manufacturer, tire model, and wheel width.
What Is 325/60R20 in Inches?
The tire size 325/60R20 describes a metric tire’s width, sidewall height, construction, and wheel diameter. The number 325 represents the tire width in millimeters, while 60 indicates that the sidewall height equals 60% of the width. The letter R means radial construction, and 20 indicates a 20-inch wheel diameter. When converted, a 325/60R20 tire is approximately 35.35 inches in overall diameter and 12.80 inches wide. These dimensions help drivers compare tire sizes before purchasing replacements.
For example, if you are checking whether a tire will fit your truck, measuring its overall diameter helps you compare it with your existing tires. However, you should also check the manufacturer’s fitment recommendations, wheel specifications, and available clearance.
Formula to Convert 325/60R20 to Inches
A tire size uses millimeters for its width and percentage for its aspect ratio, while the wheel diameter is expressed in inches. To calculate the tire’s dimensions, first convert the width from millimeters to inches and then calculate the sidewall height.
The conversion formula is:
- Width in inches = Tire width in millimeters ÷ 25.4
- Sidewall height in inches = Tire width × Aspect ratio ÷ 100 ÷ 25.4
- Overall diameter = Wheel diameter + (2 × Sidewall height)
The number 25.4 is used because one inch equals exactly 25.4 millimeters.
Step-by-Step Calculation for 325/60R20
Step 1: Identify the tire measurements.
- Tire width: 325 mm
- Aspect ratio: 60%
- Wheel diameter: 20 inches
Step 2: Convert the tire width.
325 ÷ 25.4 = 12.7953 inches
Rounded to two decimal places, the width is 12.80 inches.
Step 3: Calculate the sidewall height.
325 × 60 ÷ 100 = 195 mm
195 ÷ 25.4 = 7.6772 inches
The sidewall height is approximately 7.68 inches.
Step 4: Calculate the overall tire diameter.
20 + (2 × 7.6772) = 35.3544 inches
Therefore, the overall diameter is approximately 35.35 inches.
The calculated diameter represents the nominal size based on the tire code. The actual mounted tire may measure slightly differently.
Two More Tire Conversion Examples
Example 1: 315/60R20
- Width: 315 ÷ 25.4 = 12.40 inches
- Sidewall height: 315 × 0.60 ÷ 25.4 = 7.44 inches
- Overall diameter: 20 + (2 × 7.4409) = 34.88 inches
A 315/60R20 tire has an approximate overall diameter of 34.88 inches.
Example 2: 325/65R20
- Width: 325 ÷ 25.4 = 12.80 inches
- Sidewall height: 325 × 0.65 ÷ 25.4 = 8.32 inches
- Overall diameter: 20 + (2 × 8.3169) = 36.63 inches
A 325/65R20 tire has an approximate overall diameter of 36.63 inches.
These examples show how changing the aspect ratio affects the tire’s overall height, even when the wheel diameter remains the same.
325/60R20 to Inches Conversion Chart
The following chart compares 12 tire sizes that use 20-inch wheels. The measurements are calculated from the tire codes and rounded to two decimal places.
| Tire Size | Width (inches) | Sidewall Height (inches) | Overall Diameter (inches) |
|---|---|---|---|
| 285/60R20 | 11.22 | 6.73 | 33.46 |
| 295/60R20 | 11.61 | 6.97 | 33.94 |
| 305/55R20 | 12.01 | 6.60 | 33.21 |
| 305/60R20 | 12.01 | 7.20 | 34.41 |
| 315/60R20 | 12.40 | 7.44 | 34.88 |
| 315/65R20 | 12.40 | 8.06 | 36.12 |
| 325/50R20 | 12.80 | 6.40 | 32.80 |
| 325/55R20 | 12.80 | 7.04 | 34.07 |
| 325/60R20 | 12.80 | 7.68 | 35.35 |
| 325/65R20 | 12.80 | 8.32 | 36.63 |
| 335/55R20 | 13.19 | 7.25 | 34.51 |
| 335/60R20 | 13.19 | 7.91 | 35.83 |
The 325/60R20 entry shows the target tire’s calculated dimensions: 12.80 inches wide and 35.35 inches in overall diameter.
How to Read the Chart
The width column shows how wide each tire is from sidewall to sidewall, based on the nominal measurement. The sidewall column indicates the height of one sidewall, while the overall diameter includes both sidewalls and the wheel diameter.
Notice that two tires can have the same width but different overall diameters. For example, the 325/50R20 and 325/65R20 both have a nominal width of 12.80 inches, but their overall diameters are 32.80 and 36.63 inches, respectively.
This difference occurs because the aspect ratio determines the sidewall height. A higher aspect ratio generally produces a taller tire when the width and wheel diameter remain unchanged.
The values in this chart are mathematical estimates, not guarantees of actual installed dimensions. Always consult the specifications for the exact tire model you intend to purchase.
Common Uses of This Conversion
1. Choosing Replacement Tires for Trucks and SUVs
Drivers often convert 325/60R20 into inches to understand the size of a replacement tire. Knowing that its calculated diameter is approximately 35.35 inches makes it easier to compare it with other tire sizes.
Before purchasing, confirm that the tire is compatible with your vehicle, wheel width, suspension, and manufacturer-approved fitment specifications.
2. Checking Wheel-Well and Suspension Clearance
Overall tire diameter is an important measurement when checking whether a tire may fit inside a truck or SUV’s wheel well. A taller tire can reduce the available clearance around suspension components and body panels.
The calculated diameter provides a useful starting point, but it cannot confirm fitment on its own. Steering clearance, suspension travel, wheel offset, and vehicle modifications also matter.
3. Comparing Tire Sizes Before Upgrading
Some vehicle owners compare tire sizes when considering an upgrade for appearance, ground clearance, or off-road driving. Converting tire dimensions into inches makes comparisons easier when product listings use different measurement systems.
For example, the calculated 35.35-inch diameter of a 325/60R20 tire can be compared with the diameter of an alternative tire. Remember that changes in tire diameter can affect speedometer readings, gearing, and vehicle behavior.
Frequently Asked Questions
Q1: What is 325/60R20 in inches?
A 325/60R20 tire has a calculated overall diameter of approximately 35.35 inches, a nominal width of 12.80 inches, and a sidewall height of 7.68 inches.
The R indicates radial construction, and the final number, 20, represents the wheel diameter in inches. Actual tire dimensions may vary slightly by model.
Q2: How do I convert 325/60R20 to inches?
First, divide the width in millimeters by 25.4 to convert it to inches. Then multiply the width by the aspect ratio expressed as a decimal and divide by 25.4 to find the sidewall height.
For the overall diameter, add the wheel diameter to twice the sidewall height. For this tire, the calculation is 20 + (2 × 7.6772), giving approximately 35.35 inches.
Q3: What is the difference between 325/60R20 and 325/65R20?
A 325/60R20 tire has an approximate diameter of 35.35 inches, while a 325/65R20 tire measures approximately 36.63 inches in diameter.
The difference is 36.63 − 35.35 = 1.28 inches, using the rounded diameters. The 325/65R20 tire is taller because its sidewall height is 65% of its width instead of 60%.
Both sizes have the same nominal width of approximately 12.80 inches and are designed for 20-inch wheels, but that does not automatically mean they are interchangeable for every vehicle.
Q4: Can I use a 325/60R20 tire on any 20-inch wheel?
No. The fact that a tire is designed for a 20-inch wheel does not mean it fits every wheel with that diameter.
You must also verify the wheel’s width, the tire manufacturer’s approved rim-width range, load capacity, speed rating, and vehicle compatibility. Check the vehicle manual and tire manufacturer’s specifications before installing the tire.
Q5: Is a 325/60R20 tire big or small?
A 325/60R20 tire is relatively wide and tall compared with many standard passenger-car tires. Its calculated width is about 12.80 inches, and its overall diameter is approximately 35.35 inches.
That size is often associated with larger trucks and SUVs, but whether it is considered large for a particular vehicle depends on the vehicle’s original tire specifications and intended use.
Final Thoughts
Converting 325/60R20 in inches helps you understand the tire’s width, sidewall height, and overall diameter before comparing replacement options.
The key calculated measurements are 35.35 inches in overall diameter, 12.80 inches in width, and 7.68 inches in sidewall height. The wheel diameter is 20 inches.
Use these calculations as a reference when comparing tire sizes, but always verify the exact tire manufacturer’s specifications and your vehicle’s fitment requirements before making a purchase.
