315/35R21 Tire Size Specifications & Compatible Vehicles
Overall Diameter
753.9 mm
Section Width
315 mm
Sidewall Height
110.3 mm
Circumference
2368.4 mm
Revs/Mile
679
Rim Diameter
21"
Inch Equivalent
29.7x12.4R21
Rim Width (ETRTO)
10.0" – 12.5"
Alternative Tire Sizes
These tire sizes are within 3% overall diameter of 315/35R21 and may be used as replacements:
Understanding 315/35R21
The tire size 315/35R21 means the tire has a section width of 315mm, an aspect ratio of 35% (the sidewall height is 35% of the width), and fits a 21-inch rim.
Sidewall Height = 315 x 0.35 = 110.3 mm
Overall Diameter = (110.3 x 2) + (21 x 25.4) = 753.9 mm
Circumference = 753.9 x π = 2368.4 mm
Overall Diameter = (110.3 x 2) + (21 x 25.4) = 753.9 mm
Circumference = 753.9 x π = 2368.4 mm
Frequently Asked Questions
The 315/35R21 is a standard tire size. Check your vehicle door jamb sticker or owner manual to confirm compatibility.
A 315/35R21 tire has an overall diameter of 753.9mm (29.7 inches). The sidewall height is 110.3mm, and the total circumference is 2368mm.
For 315/35R21 tires, the ETRTO recommended rim width is 11.0". The acceptable range is 10.0" minimum to 12.5" maximum. Using a rim outside this range can cause improper bead seating and unsafe handling.
Yes, as long as the replacement tire overall diameter is within 3% of the 315/35R21 753.9mm diameter. Compatible alternatives include 245/45R21, 205/60R20, 195/50R22. Use our Tire Size Calculator to compare any two sizes.