305/40R22
Overall diameter 802.8 mm
305/40R22 — 802.8 mm tall, and what it swaps with
305/40R22 is 305 mm wide with a 40% sidewall on a 22-inch wheel. That sidewall is 122 mm, so the tyre stands 802.8 mm tall and turns 396.5 times per kilometre.
- Section width
- 305 mm
- Aspect ratio
- 40 %
- Wheel size
- 22 in (558.8 mm)
- Sidewall height
- 122 mm
- Overall diameter
- 802.8 mm (31.61 in)
- Circumference
- 2522.1 mm
- Turns per km
- 396.5
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.
265/70R17802.8 mm · 0% 265/75R16803.9 mm · +0.14% you go faster275/45R22806.3 mm · +0.44% you go faster275/55R20810.5 mm · +0.96% you go faster285/50R20793 mm · -1.22% you go slower275/65R18814.7 mm · +1.48% you go faster285/45R22815.3 mm · +1.56% you go faster285/40R22786.8 mm · -1.99% you go slower325/35R22786.3 mm · -2.06% you go slower275/45R21780.9 mm · -2.73% you go slower
Same profile, different width
Other sizes for this wheel
22-inch wheels
255/30R22 711.8mm255/35R22 737.3mm265/30R22 717.8mm265/35R22 744.3mm265/40R22 770.8mm275/35R22 751.3mm275/40R22 778.8mm275/45R22 806.3mm285/25R22 701.3mm285/35R22 758.3mm285/40R22 786.8mm285/45R22 815.3mm295/30R22 735.8mm295/35R22 765.3mm305/30R22 741.8mm305/40R22 802.8mm315/25R22 716.3mm325/35R22 786.3mm
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 305/40R22?
802.8 mm — the 558.8 mm wheel plus the 122 mm sidewall at top and bottom.
Q. How many turns per kilometre does 305/40R22 make?
Its circumference is 2522.1 mm, so 396.5 turns.
Q. What can I swap it for?
10 sizes stay within 3% of its diameter — the closest is 265/70R17 at 802.8 mm.
Q. Why is the sidewall 122 mm?
Because it is 40% of the 305 mm width. The aspect ratio is a proportion of the width, not a length.