Car Tire Size Chart And Sizing Guide

January 23, 2022January 23, 2022 by Egle Goleckyte

When your car’s tires are too small, it can be dangerous to drive on the highway. The car will be more difficult to control and you may end up in a serious accident. On the other hand, if your car has oversized tires, it may be too difficult to turn and accelerate. Your car could end up in a skid, which is dangerous as well. Read on how to use a car tire size chart to find the correct tire size for your car and for optimal performance.

Looking for branded Car tires sizes? Check the Michelin, Continental, Goodyear,… size charts

How To Use The Car Tire Size Chart?

The car tire size chart is simple to use. The first step is to figure out what tire type you have on your car. There are three types: radial, bias-ply, and belted bias. You can usually tell by looking at the sidewall of the tire. If you see letters, then you have bias-ply tires. If there are numbers on the sidewall, then your car has radial tires.

Belted bias tires look like they’re made of rubber bands. To know if your tire is a belted bias or not, you must check the tread pattern. If it looks like an “S” shape, then it’s a belted bias.

The chart below is to help you cross-reference between the different sizes and base on the different types of the car tire.

Radial Tire and Bias-Ply Cross-Reference Size Chart
Models Pre-1964	1965 to 1972	80 series metric	Alpha Numeric 78 Series	Alpha Numeric 70 Series	P-Metric Tires (75 series Radial)	P-Metric Sizes (70 Series Radial)	Recommended rim size in inches	Recommended rim size in mm
520-12	–	125-12	–	–	P125/75R12	–	4-5	102-127
520-13	560-13	155-13	–	–	P155/75R13	P155/70R13	4-5	102-127
590-13	600-13	165-13	A78-13	–	P165/75R13	P175/70R13	4-5	102-127
640-13	650-13	175-13	B78-13	–	P175/75R13	P185/70R13	4-6	102-152
725-13	700-13	185-13	D78-13	–	P185/75R13	P205/70R13	4-6	102-152
590-14	645-14	155-14	B78-14	–	P175/75R14	P185/70R14	4-6	102-152
650-14	695-14	175-14	C78-14	–	P185/75R14	P195/70R14	4-6	102-152
700-14	735-14	185-14	E78-14	E70-14	P195/75R14	P205/70R14	4-6	102-152
750-14	775-14	195-14	F78-14	F70-14	P205/75R14	P215/70R14	4-6	102-152
800-14	825-14	205-13	G78-14	G70-14	P215/75R14	P225/70R14	5-7	127-178
850-14	855-14	215-14	H78-14	–	P225/75R14	P235/70R14	5-7	127-178
590-16	600-15	165-15	A78-15	–	P165/75R15	P175/70R15	4-5	102-127
640-15	685-15	175-15	C78-15	–	P175/75R15	P185/70R15	5-6	127-152
650-15	735-15	185-15	E78-15	E70-15	P195/75R15		5-6	127-152
670-15	775-15	195-15	F78-15	F70-15	P205/75R15	P215/70R15	5-7	127-178
710-15	825-15	205-15	G78-15	G70-15	P215/75R15	P225/70R15	6-8	152-203
760-15	855-15	215-25	H78-15	H70-15	P225/75R15	P235/70R15	6-8	152-203
800-15	885-15	230-15	J78-15	K70-15	P235/75R15	P235/70R15	6-8	152-203
820-15	900-15	235-15	L78-15	L70-15	P235/75R15	P255/70R15	6-8	152-203

Pro Tip: Always consult your car owner’s manual before making any changes to your car. The car tire size chart is just a guide to help you make the best decision for your vehicle.

How To Read Your Sidewall Marking on Tires?

car tire size how to read measurements explained

Sidewalls of tires usually have markings that show tire information. Here are some of the information you can get.

A. Class of tire

The class of tire will be indicated on the tire wall. P stands for passenger car tires such as crossovers, SUVs. L stands for a light truck tire. This is designed for cars for towing cars. ST is for special trailers such as cars with fifth wheels, boats, and winter tires.

If the tire did not have a letter, it is in metric measurement wherein the measurement is in millimeters.

B. Section width

This is the tire’s width. Look for the number to see how wide your tires are in millimeters. In the image above, the section width is 215 millimeters (8.46 inches). How to measure the tire width? You will need to measure the distance from the sidewall edge across to the opposite side.

C. Aspect ratio

This is the tire’s height-to-width ratio and is usually indicated by a letter such as 80, 70, or 60 (80 means that it has an aspect ratio of 80%.) The higher the number, the taller your tire is. How to measure the tire sidewall height? You will need to measure the tire sidewall height from rim edge to tread face.

D. Construction Type

This indicates the type of construction inside the tire. The two most common types are radial and bias-ply. R stands for radial while B stands for bias-ply. Radial construction type means that the cords that run across the tire are at a 90-degree angle to the direction of travel. This type is usually used on modern cars. Bias-ply construction type means that the cords are at an angle less than 90 degrees and were more commonly used in older vehicles.

E. Wheel Diameter

Wheel diameter also known as wheel rim diameter indicates the tire’s outer width. It is usually measured in inches and can be found on your car owner’s manual or door jamb sticker.

F. Load Index

This number ranges from 65 to 150 which measures the load-carrying capacity of a tire when properly inflated for inflation pressure at maximum load, but should never be used as the only indicator of tire safety. Carrying too much weight on a tire can overload it and will cause sidewall failure, blowouts, or catastrophic damage. Consult your car owner’s manual to find out how much weight your vehicle can safely carry.

Here’s a table of the load capacity based on load index.

Load Index	Load Capacity (lbs)	Load Capacity (kg)
65	639	289.85
66	661	299.82
67	677	307.08
68	694	314.79
69	716	324.77
70	739	335.20
71	761	345.18
72	783	355.16
73	805	365.14
74	827	375.12
75	853	386.91
76	882	400.07
77	908	411.86
78	937	425.02
79	963	436.81
80	992	449.96
81	1019	462.21
82	1047	474.91
83	1074	487.16
84	1102	499.86
85	1135	514.83
86	1168	529.80
87	1201	544.76
88	1235	560.19
89	1279	580.14
90	1323	600.10
91	1356	615.07
92	1389	630.04
93	1433	650.00
94	1477	669.96
95	1521	689.91
96	1565	709.87
97	1609	729.83
98	1653	749.79
99	1709	775.19
100	1764	800.14
101	1819	825.08
102	1874	850.03
103	1929	874.98
104	1984	899.93
105	2039	924.87
106	2094	949.82
107	2149	974.77
108	2205	1000.17
109	2271	1030.11
110	2337	1060.05
111	2403	1089.98
112	2469	1119.92
113	2535	1149.86
114	2601	1179.79
115	2679	1215.17
116	2756	1250.10
117	2833	1285.03
118	2910	1319.95
119	2998	1359.87
120	3086	1399.79
121	3197	1450.13
122	3307	1500.03
123	3417	1549.93
124	3527	1599.82
125	3638	1650.17
126	3748	1700.06
127	3858	1749.96
128	3968	1799.85
129	4079	1850.20
130	4189	1900.10
131	4299	1949.99
132	4409	1999.89
133	4541	2059.76
134	4674	2120.09
135	4806	2179.96
136	4938	2239.84
137	5071	2300.17
138	5203	2360.04
139	5357	2429.89
140	5512	2500.20
141	5677	2575.04
142	5842	2649.89
143	6008	2725.18
144	6173	2800.03
145	6393	2899.82
146	6614	3000.06
147	6779	3074.90
148	6944	3149.75
149	7165	3249.99
150	7385	3349.78

In the image above, the load index is 95 so the load capacity is 1521 lbs (689.91 kgs).

G. Speed Rating

This letter is an indication of the maximum speed that the tire is capable of. Speed ratings are A1 to (Y). Higher ratings mean a higher top speed for your car. Consult your car owner’s manual to find out what speed rating your vehicle should have.

Tire Speed Ratings	Speed
A1	3
A2	6
A3	9
A4	12
A5	16
A6	19
A7	22
A8	25
B	31
C	37
D	40
E	43
F	50
G	56
J	62
K	68
L	75
M	81
N	87
P	93
Q	99
R	106
S	112
T	118
U	124
H	130
V	149
W	168
Y	186
(Y)	Above 186

In the image above, the speed rating is V which has a maximum speed of 149 mph.

Car Tires Sizing explained (video)

Full Car tires sizes explained by Autobytel

Conclusion on car tires sizing

Car tires are an important component of your car, providing grip to the ground while traveling at different speeds. They also provide stability for normal driving conditions as well as when braking or turning corners. The right sizes of car tires can make a big difference in safety, performance, and fuel efficiency so it’s important to understand how they work before buying new ones for your vehicle.

Picture in this post by LOGAN WEAVER on Unsplash