GarageCalc What 175/70R14 means
175 is the section width in millimeters (6.9 in). 70 is the aspect ratio: the sidewall is 70 percent of the width, so 175 × 0.70 = 123 mm (4.8 in). R is radial construction, and 14 is the wheel diameter in inches (356 mm). Stack two sidewalls on the wheel and you get the overall diameter: 356 + 2 × 123 = 601 mm, or 23.6 in.
A full marking adds a load index and speed rating after the size, for example 175/70R14 91V. Those two codes set how much weight and speed the tire is certified for; look them up in the load index chart and the speed rating chart.
Plus and minus sizing from 175/70R14
Similar diameter does not establish interchangeability. Follow the vehicle manufacturer's approved sizes; see Michelin's tire-size guidance.
Going up one wheel size, the closest match is 185/60R15 at +0.4% diameter with a 111 mm sidewall instead of 123 mm. Going down one size, 165/80R13 is -1.1% with a taller 132 mm sidewall for more comfort and pothole margin. The 3 percent cutoff is a comparison filter, not a fitment approval. Use vehicle-approved sizes and check rim width, load and speed ratings, and clearances. The comparison calculator shows the full speedometer table for any pair.
Frequently asked questions
How tall is a 175/70R14 tire?
23.6 inches (601 mm) in overall diameter: the 14-inch wheel (356 mm) plus two 123 mm sidewalls. Actual dimensions depend on the tire model, tread depth, pressure and load; check the tire manufacturer specifications.
What is 175/70R14 in inches?
23.6 x 6.9 R14: 23.6 inches tall, 6.9 inches wide, on a 14-inch wheel. The sidewall is 4.8 inches and the circumference is 74.3 inches, so the tire turns 853 times per mile.
What tire sizes are equivalent to 175/70R14?
Within 3 percent of the same diameter on the same 14-inch wheel: 185/65R14 (-0.7%), 195/65R14 (+1.4%), 195/60R14 (-1.8%); on a 15-inch wheel: 185/60R15 (+0.4%), 165/65R15 (-0.8%); on a 13-inch wheel: 165/80R13 (-1.1%), 185/70R13 (-1.9%). The percentage is the diameter change, which is also your speedometer error.
Can I use 185/65R14 instead of 175/70R14?
Nominal size comparison only: 185/65R14 is 0.7% shorter (-5 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 60.5 mph. This does not confirm fitment. Check approved rim widths, load and speed ratings, and vehicle clearances. The nominal extra width adds about 0.20 in of clearance on each side of the tire and a rim width that suits 185 mm.