325/30R21 Tire Size in Inches and Millimeters
325/30R21 tires have a diameter of 28.7" (729 mm), a tread width of 12.8" (325 mm), and a wheel diameter of 21" (533.4 mm).The sidewall of the tire is 3.9" (98 mm), and the tire's circumference is 90.1" (2289.1 mm). This means a 325/30R21 tire will make make 703 revolutions per mile, or 437 revolutions per kilometer.
| Spec | Inches | Metric |
|---|---|---|
| Diameter | 28.7" | 729 mm |
| Width | 12.8" | 325 mm |
| Wheel | 21" | 533.4 mm |
| Sidewall | 3.9" | 98 mm |
| Circum | 90.1" | 2289.1 mm |
| Revolutions | 703 per mile | 437 per km |
What Does 325/30R21 Mean?
The tire size 325/30R21 is a common size used on many trucks, SUVs, and other larger vehicles.
Here is what each part of the size designation represents:
- 325: This number represents the width of the tire in millimeters. In this case, the tire is 325 millimeters wide.
- 30: This number represents the aspect ratio of the tire, which is the height of the tire's sidewall as a percentage of its width. In this case, the sidewall height is 30% of the tire's width.
- R: This letter indicates the tire's construction type. “R” stands for radial construction, which is the most common type of tire construction today.
- 21: This number represents the diameter of the wheel that the tire is designed to fit on, in inches. In this case, the tire is designed to fit on a 21-inch wheel.
How To Convert 325/30R21 Into Inches
The 325/30R21 conversion is fairly simple. The first number in the tire size, 325, represents the width of the tire in millimeters. To convert this to inches, we divide 325 by 25.4 (since there are 25.4 millimeters in an inch). This gives us approximately 12.8 inches.
The second number in the tire size, 30, represents the aspect ratio or the height of the tire as a percentage of its width. To calculate the height in inches, we multiply 12.8 by 0.30, which gives us approximately 3.9 inches.
Finally, the last number in the tire size, 21, represents the diameter of the wheel rim in inches. Therefore, the tire size 325/30R21 can be expressed in inches as roughly 12.8 inches wide, 3.9 inches tall, and designed to fit a 21-inch wheel rim.
Frequently Asked Questions About 325/30R21 Tires
How tall is a 325/30R21 tire?
A 325/30R21 tire has an approximate height, also known as the overall diameter, of 28.7 inches (729 mm). This height can vary slightly depending on the brand and model of the tire, as well as the amount of air pressure in the tire.How wide is a 325/30R21 tire?
A 325/30R21 tire has a width of approximately 12.8 inches (325 millimeters). The width of the tire is the first number in the tire size designation, which in this case is “325”. It’s important to note that the actual width of the tire may vary slightly depending on the brand and model of the tire, and the width may also be affected by the amount of air pressure in the tire.Alternate 325/30R21 Replacement Tire Sizes
Upsizing your wheels or tires? Replacement tires must be within 3% of the diametor of the original tire. The following sizes fall within that range - click on any size to see detailed info about that tire and wheel combination.
| Size | Diameter | Width | Wheel |
|---|---|---|---|
| 145/80R19 | 28.1" | 715 mm | 19 mm |
| 145/80R20 | 29.1" | 740 mm | 20 mm |
| 155/65R20 | 28" | 710 mm | 20 mm |
| 155/80R19 | 28.8" | 731 mm | 19 mm |
| 155/85R18 | 28.4" | 721 mm | 18 mm |
| 155/90R17 | 28" | 712 mm | 17 mm |
| 155/90R18 | 29" | 737 mm | 18 mm |
| 165/90R17 | 28.7" | 730 mm | 17 mm |
| 175/80R18 | 29" | 737 mm | 18 mm |
| 175/90R17 | 29.4" | 748 mm | 17 mm |
| 195/80R16 | 28.3" | 718 mm | 16 mm |
| 205/75R16 | 28.1" | 714 mm | 16 mm |
| 205/80R16 | 28.9" | 734 mm | 16 mm |
| 215/65R17 | 28" | 712 mm | 17 mm |
| 215/70R16 | 27.9" | 708 mm | 16 mm |
| 215/70R17 | 28.9" | 734 mm | 17 mm |
| 215/75R16 | 28.7" | 728 mm | 16 mm |
| 215/80R15 | 28.5" | 725 mm | 15 mm |
| 215/80R16 | 29.5" | 750 mm | 16 mm |
| 215/85R15 | 29.4" | 747 mm | 15 mm |
| 225/45R20 | 28" | 710 mm | 20 mm |
| 225/55R19 | 28.8" | 731 mm | 19 mm |
| 225/60R18 | 28.6" | 727 mm | 18 mm |
| 225/65R17 | 28.5" | 724 mm | 17 mm |
| 225/65R18 | 29.5" | 749 mm | 18 mm |
| 225/70R16 | 28.4" | 722 mm | 16 mm |
| 225/70R17 | 29.4" | 748 mm | 17 mm |
| 225/75R15 | 28.3" | 719 mm | 15 mm |
| 225/75R16 | 29.3" | 744 mm | 16 mm |
| 225/80R15 | 29.2" | 741 mm | 15 mm |
| 235/45R20 | 28.3" | 720 mm | 20 mm |
| 235/45R21 | 29.3" | 745 mm | 21 mm |
| 235/50R19 | 28.3" | 719 mm | 19 mm |
| 235/50R20 | 29.3" | 744 mm | 20 mm |
| 235/55R18 | 28.1" | 715 mm | 18 mm |
| 235/55R19 | 29.2" | 741 mm | 19 mm |
| 235/60R17 | 28.1" | 714 mm | 17 mm |
| 235/60R18 | 29.1" | 739 mm | 18 mm |
| 235/65R16 | 28" | 712 mm | 16 mm |
| 235/65R17 | 29.1" | 738 mm | 17 mm |
| 235/70R15 | 28" | 711 mm | 15 mm |
| 235/70R16 | 29" | 736 mm | 16 mm |
| 235/75R15 | 28.9" | 733 mm | 15 mm |
| 245/25R24 | 28.8" | 732 mm | 24 mm |
| 245/35R22 | 28.8" | 731 mm | 22 mm |
| 245/40R21 | 28.7" | 729 mm | 21 mm |
| 245/45R20 | 28.7" | 728 mm | 20 mm |
| 245/50R19 | 28.7" | 729 mm | 19 mm |
| 245/55R18 | 28.6" | 727 mm | 18 mm |
| 245/60R17 | 28.6" | 726 mm | 17 mm |
| 245/65R17 | 29.5" | 750 mm | 17 mm |
| 245/70R15 | 28.5" | 725 mm | 15 mm |
| 245/70R16 | 29.5" | 750 mm | 16 mm |
| 245/75R15 | 29.5" | 749 mm | 15 mm |
| 255/25R24 | 29.1" | 738 mm | 24 mm |
| 255/30R22 | 28.1" | 713 mm | 22 mm |
| 255/35R21 | 28" | 711 mm | 21 mm |
| 255/35R22 | 29" | 737 mm | 22 mm |
| 255/40R20 | 28" | 712 mm | 20 mm |
| 255/40R21 | 29" | 737 mm | 21 mm |
| 255/45R19 | 28.1" | 713 mm | 19 mm |
| 255/45R20 | 29.1" | 738 mm | 20 mm |
| 255/50R18 | 28.1" | 713 mm | 18 mm |
| 255/50R19 | 29.1" | 739 mm | 19 mm |
| 255/55R17 | 28" | 712 mm | 17 mm |
| 255/55R18 | 29" | 737 mm | 18 mm |
| 255/60R16 | 28" | 712 mm | 16 mm |
| 255/60R17 | 29.1" | 738 mm | 17 mm |
| 255/65R15 | 28.1" | 713 mm | 15 mm |
| 255/65R16 | 29.1" | 738 mm | 16 mm |
| 255/70R15 | 29.1" | 739 mm | 15 mm |
| 265/25R23 | 28.2" | 716 mm | 23 mm |
| 265/25R24 | 29.2" | 742 mm | 24 mm |
| 265/30R22 | 28.3" | 719 mm | 22 mm |
| 265/35R21 | 28.3" | 719 mm | 21 mm |
| 265/35R22 | 29.3" | 745 mm | 22 mm |
| 265/40R20 | 28.3" | 720 mm | 20 mm |
| 265/40R21 | 29.3" | 745 mm | 21 mm |
| 265/45R19 | 28.4" | 721 mm | 19 mm |
| 265/45R20 | 29.4" | 746 mm | 20 mm |
| 265/50R18 | 28.5" | 723 mm | 18 mm |
| 265/50R19 | 29.5" | 749 mm | 19 mm |
| 265/55R17 | 28.5" | 724 mm | 17 mm |
| 265/55R18 | 29.5" | 749 mm | 18 mm |
| 265/60R16 | 28.5" | 724 mm | 16 mm |
| 265/60R17 | 29.5" | 750 mm | 17 mm |
| 265/65R16 | 29.5" | 750 mm | 16 mm |
| 275/23R24 | 29" | 736 mm | 24 mm |
| 275/25R24 | 29.4" | 748 mm | 24 mm |
| 275/30R22 | 28.5" | 725 mm | 22 mm |
| 275/35R21 | 28.5" | 725 mm | 21 mm |
| 275/40R20 | 28.7" | 728 mm | 20 mm |
| 275/45R19 | 28.8" | 731 mm | 19 mm |
| 275/50R17 | 27.9" | 708 mm | 17 mm |
| 275/50R18 | 28.9" | 733 mm | 18 mm |
| 275/55R16 | 27.9" | 708 mm | 16 mm |
| 275/55R17 | 28.9" | 734 mm | 17 mm |
| 275/60R15 | 28" | 711 mm | 15 mm |
| 275/60R16 | 29" | 736 mm | 16 mm |
| 285/30R22 | 28.8" | 731 mm | 22 mm |
| 285/35R20 | 27.9" | 708 mm | 20 mm |
| 285/35R21 | 28.9" | 733 mm | 21 mm |
| 285/40R19 | 28" | 711 mm | 19 mm |
| 285/40R20 | 29" | 736 mm | 20 mm |
| 285/45R18 | 28.1" | 713 mm | 18 mm |
| 285/45R19 | 29.1" | 739 mm | 19 mm |
| 285/50R18 | 29.3" | 743 mm | 18 mm |
| 285/60R16 | 29.4" | 748 mm | 16 mm |
| 295/23R24 | 29.4" | 746 mm | 24 mm |
| 295/30R21 | 28" | 711 mm | 21 mm |
| 295/30R22 | 29" | 737 mm | 22 mm |
| 295/35R20 | 28.1" | 714 mm | 20 mm |
| 295/35R21 | 29.1" | 739 mm | 21 mm |
| 295/40R19 | 28.3" | 719 mm | 19 mm |
| 295/40R20 | 29.3" | 744 mm | 20 mm |
| 295/45R18 | 28.5" | 723 mm | 18 mm |
| 295/45R19 | 29.5" | 749 mm | 19 mm |
| 295/60R15 | 28.9" | 735 mm | 15 mm |
| 305/25R22 | 28" | 711 mm | 22 mm |
| 305/25R23 | 29" | 736 mm | 23 mm |
| 305/30R21 | 28.2" | 717 mm | 21 mm |
| 305/30R22 | 29.3" | 743 mm | 22 mm |
| 305/35R20 | 28.4" | 722 mm | 20 mm |
| 305/35R21 | 29.4" | 747 mm | 21 mm |
| 305/45R18 | 28.8" | 731 mm | 18 mm |
| 315/25R22 | 28.2" | 717 mm | 22 mm |
| 315/25R23 | 29.2" | 742 mm | 23 mm |
| 315/30R21 | 28.5" | 723 mm | 21 mm |
| 315/30R22 | 29.5" | 749 mm | 22 mm |
| 315/35R20 | 28.7" | 728 mm | 20 mm |
| 315/40R18 | 27.9" | 709 mm | 18 mm |
| 315/40R19 | 28.9" | 735 mm | 19 mm |
| 315/45R17 | 28.2" | 716 mm | 17 mm |
| 325/30R21 | 28.7" | 729 mm | 21 mm |
| 325/35R20 | 29" | 736 mm | 20 mm |
| 325/45R18 | 29.5" | 749 mm | 18 mm |
| 335/25R22 | 28.6" | 727 mm | 22 mm |
| 335/30R20 | 28" | 710 mm | 20 mm |
| 345/30R20 | 28.2" | 716 mm | 20 mm |
| 345/35R19 | 28.5" | 725 mm | 19 mm |
| 345/40R17 | 27.9" | 708 mm | 17 mm |
| 355/25R21 | 28" | 711 mm | 21 mm |