How to read the numbers on your sidewall

The ratio between a tyre's sidewall height and its width, shown as a percentage in the tyre size marking. A 100/90 tyre has a sidewall height that is 90% of its 100mm width, affecting how the bike handles and rides over potholes or uneven roads.

A certification mark from the Bureau of Indian Standards (BIS) that confirms a tyre meets mandatory safety and quality standards for sale in India. All two-wheeler tyres legally sold in the country must carry this mark on the sidewall.

DOT code refers to the Department of Transportation marking stamped on the tyre sidewall. It shows the factory, size code, and manufacturing date. The last four digits indicate the week and year of manufacture.

A tyre built with stronger internal construction to carry heavier loads than a standard tyre of the same size. Useful for riders who frequently carry a pillion passenger or luggage on Indian highways.

A numerical code on the tyre sidewall that indicates the maximum weight (in kilograms) a single tyre can safely carry at proper inflation pressure. For example, a load index of 54 means the tyre can handle 212 kg per tyre.

A letter code (A, B, C, etc.) stamped on the tyre sidewall that indicates its load-carrying capacity and ply strength. Higher letters mean the tyre can handle more weight, which matters when riding with a pillion or carrying luggage on Indian roads.

Overall diameter is the complete height of a tyre measured from the bottom of the tread to the top when mounted on a rim and fully inflated. This measurement affects your bike's ground clearance, speedometer reading, and handling on Indian roads.

A rating that shows a tyre's strength and load-carrying ability. Modern tyres use fewer but stronger plies (fabric or steel layers inside the tyre), so the rating now indicates strength rather than actual layer count.

PSI stands for "Pounds per Square Inch", the unit that measures air pressure in your tyre. Correct PSI keeps your bike stable, improves fuel efficiency, and prevents uneven tread wear.

The R marking on a tyre sidewall indicates radial construction, where internal cords run straight across from side to side. Radial tyres offer better grip, longer life, and heat resistance than older bias-ply tyres.

The measurement across the wheel rim where the tyre sits, expressed in inches. This number determines which tyres fit your bike or scooter; a 17-inch rim requires a 17-inch tyre, common on many 150cc bikes in India.

The distance across the inside of your wheel rim, measured from edge to edge. This measurement determines which tyre sizes will fit your bike or scooter correctly and safely.

The height of the tyre's sidewall measured from the wheel rim to the tread surface. Section height affects ride comfort and handling; a taller sidewall absorbs bumps better on broken roads, while a shorter one improves cornering response.

The width of a tyre measured from one sidewall to the other, expressed in millimeters. Wider section widths provide more grip on monsoon roads and carry pillion riders better, while narrower tyres typically offer better fuel economy for daily city use.

The set of numbers and letters on your tyre's sidewall (like 100/90-17) that indicates its width in millimeters, height-to-width ratio as a percentage, and the rim diameter in inches.

A letter code on the tyre sidewall that indicates the maximum safe speed the tyre can handle when properly inflated and loaded. For example, an 'H' rating means the tyre is tested up to 210 km/h.

TL (tubeless) and TT (tube type) are markings printed on the tyre sidewall that tell you whether the tyre needs an inner tube fitted or not. TL tyres seal directly against the rim without a tube, while TT tyres require an inner tube to hold air.