How to Check Your Tyre Size
                     How to Check Your Tyre Size?
Identify your tyre’s different sections
There are two types of tyre size measurements: 
metric and flotation. Metric is more commonly used 
and is more popular among consumers and we’ll be 
talking about metric sizing today.
Usually, the metric sizing is divided into 5 sections, 
but it can span up to 7 different sections. These 
sections determine the composition, weight 
capacity, maximum speed capability, and more.  
Read the sidewalls of your current tyres. On most 
tyres, the size information is right on the tyres. An 
example of this information: "P 185/75 R14 82S."
Service Type
The P stands for "passenger tyres"
The first section designates the service type. This 
refers to what type of vehicle the tyre is 
manufactured for. 
The first two letters are considered your car tyre’s 
service type.
● P – Passenger  
● LT – Light Truck  
● ST – Special Trailer 
● T – Temporary 
Some tyres don’t have letters indicating their 
service type. It’s safe to assume that these tyres are 
for passenger vehicles. 
Section Width
185 indicates the width in millimetres
This is the three-digit number that comes 
immediately after the service type. The section 
width measures the tyre’s overall width when it is 
mounted on a properly sized wheel. 
It measures the widest point of the inner sidewall to 
the widest part of the outer sidewall. Generally, 
wider tyres give more traction to the vehicle. 
However, this could also mean that it will be 
heavier, causing more fuel consumption.  
Aspect Ratio
75 refers to the height of the tyre divided by the 
width (also known as the aspect ratio)
The aspect ratio represents the height of the 
sidewall corresponding to the section width.  
The higher the number of the aspect ratio, the taller 
the sidewall. Tyres with a higher aspect ratio gives a 
more cushioned ride. It also means lesser road-
noise. Tyres with a lower aspect ratio is way better it 
terms of mobility, handling, and cornering
Construction
R indicates the radial construction
A letter that identifies the tyre's internal 
construction follows the two digits used to identify 
the aspect ratio. There are three types of tyre 
constructions: Belted Bias, Diagonal, and Radial.
Rim Diameter
14 refers to the diameter of the full tyre in inches.
The Rim Diameter can be determined by checking 
the next digits after the letter. It is one of the most 
important numbers on your tyre.
Often measured in inches, this is the wheel’s 
measurement from one end to the other.
Load Rating
82 indicates the load rating
Your tyre’s load index identifies your tyre’s 
maximum load-carrying capacity. These numbers 
are a representation of the actual pounds or 
kilogram. 
Speed Rating
S indicates the speed rating
The speed rating tells you the maximum speed your 
tyre is tested corresponding to your tyre’s load 
index. The tyre’s speed rating is also an indicator on 
the tyre’s performance capability, from traction, 
braking, and handling.
Wrap It Up
It’s always good to have an idea about your tyre size. Whenever you’re still confused in choosing the 
tyre that works for your car, it’s best to consult and visit an expert to determine the right tyre for you. 
Don’t hesitate to visit your local tyre experts and seek for help on your tyre concerns. If your around 
Sydney, visit Ryan Tyres and Batteries.
Ryan Tyres and Batteries is an automotive service provider established in 2009 and has since gained a 
reputation for offering best car tyre deals , wheels, automotive batteries and other car & truck related 
services at highly reasonable deals. 
 
THANK YOU!
Visit Ryan Tyres and Batteries
UNIT 1, 27 Phillip Street Kingswood - NSW - 2747, Sydney - Australia
www.ryantyres.com.au