245/70R17
Overall diameter 774.8 mm
245/70R17 — 774.8 mm tall, and what it swaps with
245/70R17 is 245 mm wide with a 70% sidewall on a 17-inch wheel. That sidewall is 171.5 mm, so the tyre stands 774.8 mm tall and turns 410.8 times per kilometre.
- Section width
- 245 mm
- Aspect ratio
- 70 %
- Wheel size
- 17 in (431.8 mm)
- Sidewall height
- 171.5 mm
- Overall diameter
- 774.8 mm (30.5 in)
- Circumference
- 2434.1 mm
- Turns per km
- 410.8
Sizes you can swap to
Only sizes whose overall diameter stays within 3% are listed. A different diameter covers a different distance per turn, and that gap becomes speedometer error.
265/60R18775.2 mm · +0.05% you go faster265/65R17776.3 mm · +0.19% you go faster265/50R20773 mm · -0.23% you go slower265/70R16777.4 mm · +0.34% you go faster265/45R21771.9 mm · -0.37% you go slower275/40R22778.8 mm · +0.52% you go faster265/40R22770.8 mm · -0.52% you go slower275/45R21780.9 mm · +0.79% you go faster235/55R20766.5 mm · -1.07% you go slower295/35R22765.3 mm · -1.23% you go slower325/35R22786.3 mm · +1.48% you go faster255/65R17763.3 mm · -1.48% you go slower
Same profile, different width
Other sizes for this wheel
17-inch wheels
205/40R17 595.8mm205/45R17 616.3mm205/50R17 636.8mm205/55R17 657.3mm215/45R17 625.3mm215/50R17 646.8mm215/55R17 668.3mm215/60R17 689.8mm215/65R17 711.3mm225/45R17 634.3mm225/50R17 656.8mm225/55R17 679.3mm225/60R17 701.8mm225/65R17 724.3mm235/45R17 643.3mm235/55R17 690.3mm235/60R17 713.8mm235/65R17 737.3mm245/45R17 652.3mm245/65R17 750.3mm245/70R17 774.8mm255/65R17 763.3mm265/65R17 776.3mm265/70R17 802.8mm
How the code reads
The 205 is millimetres, the 55 is a percentage of that width, and only the 16 is inches. The R stands for radial construction.
How to read this
- The first three digits are the width in mm, the middle two are the aspect ratio in percent, the last two the wheel in inches.
- Sidewall height = width × aspect ÷ 100. For 205/55 that is 112.75 mm.
- Overall diameter = wheel diameter + twice the sidewall. A 16-inch wheel is 406.4 mm.
- Once the diameter shifts by more than 3%, the speedometer and odometer drift by the same amount.
Frequently asked questions
Q. What is the overall diameter of 245/70R17?
774.8 mm — the 431.8 mm wheel plus the 171.5 mm sidewall at top and bottom.
Q. How many turns per kilometre does 245/70R17 make?
Its circumference is 2434.1 mm, so 410.8 turns.
Q. What can I swap it for?
12 sizes stay within 3% of its diameter — the closest is 265/60R18 at 775.2 mm.
Q. Why is the sidewall 171.5 mm?
Because it is 70% of the 245 mm width. The aspect ratio is a proportion of the width, not a length.