Scooter and Moped Tire Size Charts and Conversions: Reading and Comparing Sidewall Sizes

A scooter or moped tire size such as 130/70-13 gives three dimensions. The first number is the section width in millimetres (130 mm). The second is the aspect ratio, the sidewall height as a percentage of that width (70%). The last is the rim diameter in inches (13 in). Older or traditional sizes such as 3.50-10 use inches for both width and rim diameter and do not state an aspect ratio. From these numbers you can calculate a nominal sidewall height, overall diameter and circumference, which lets you compare sizes. A calculated figure is not the measured size of a real tire, and it does not confirm that a tire will fit a particular scooter.

How do you read the numbers on a scooter tire sidewall?

Read the size from left to right: width, then aspect ratio, then construction and rim diameter, then the service description (load index and speed symbol). A typical scooter marking looks like this: 130/70-13 M/C 63P TL.

Metric scooter tire sizes explained

Most modern scooters use metric tire sizes. The table breaks down the example 130/70-13 M/C 63P TL.

Marking	What it is	Unit or type	What it tells you
130	Section width	Millimetres (dimension)	Nominal width of the inflated tire from sidewall to sidewall, measured on a specified rim
70	Aspect ratio	Percentage (ratio)	Sidewall height is 70% of the width: 130 × 0.70 = 91 mm
- (dash)	Construction	Code	A dash or no letter usually means bias-ply construction. R means radial and B means bias-belted.
13	Rim diameter	Inches (dimension)	The tire fits a 13-inch rim only. 13 in = 330.2 mm.
M/C	Motorcycle use	Code	Built for motorcycles and scooters, not cars
63	Load index	Performance rating	Maximum load per tire, here 272 kg, under the conditions the standard specifies
P	Speed symbol	Performance rating	Maximum rated speed, here 150 km/h, under the conditions the standard specifies
TL	Tubeless	Code	Designed to run without an inner tube on a tubeless rim. TT means tube type.

The width, aspect ratio and rim diameter are size information. The load index and speed symbol are performance ratings. They describe what the tire is rated to carry and how fast it may be ridden, and they do not change its dimensions.

Inch tire sizes on scooters and mopeds

An inch tire size such as 3.50-10 means a nominal section width of 3.50 inches (about 88.9 mm) on a 10-inch rim. Older scooters, many mopeds and some Indian-market scooters use this format. Inch sizes do not include an aspect ratio. Traditional bias-ply inch tires have tall sidewalls, often treated as roughly equal to the width, but the real profile varies by tire. Inch-sized tires may also show a ply rating such as 4PR or 6PR. This is a strength rating carried over from older construction methods. It does not count actual plies, and it is not a dimension.

Load index and speed symbol values for scooter tires

The load index is a code number for the maximum load one tire can carry. The speed symbol is a letter for the maximum rated speed. The values below cover the ranges commonly found on scooter and moped tires.

Load index	Max load per tire	Speed symbol	Max speed
46	170 kg	J	100 km/h
48	180 kg	K	110 km/h
50	190 kg	L	120 km/h
52	200 kg	M	130 km/h
54	212 kg	N	140 km/h
56	224 kg	P	150 km/h
58	236 kg	Q	160 km/h
60	250 kg	R	170 km/h
62	265 kg	S	180 km/h
64	280 kg	T	190 km/h
66	300 kg	H	210 km/h

Read each pair of columns on its own. A load index and a speed symbol on the same row are not related. A replacement tire should generally have a load index and speed symbol at least equal to those the vehicle manufacturer specifies.

Other sidewall markings

• FRONT / REAR and a rotation arrow: the tire is designed for one wheel position and one direction of rotation.
• REINF or RF: reinforced construction for a higher load.
• DOT date code: the last four digits give the production week and year. For example, 2324 means week 23 of 2024.
• Rim marking on the wheel, such as 13 × MT3.50: stamped on the rim, not the tire. It gives the rim diameter (13 in) and rim width (3.50 in). A tire is designed for a range of rim widths.

Scooter and moped tire size chart by wheel size

Scooter wheel size usually refers to the rim diameter in inches, the last number in the tire size. Wheel size and tire size are not the same thing. Each rim diameter accepts many tire widths and profiles. The chart groups common scooter and moped sizes by rim diameter.

Rim diameter	Common tire sizes	Typical vehicles
10 in	3.00-10, 3.50-10, 90/90-10, 90/100-10, 100/90-10	Small 50 cc scooters and the rear wheel of many commuter scooters
12 in	90/90-12, 110/70-12, 120/70-12, 130/70-12	Commuter and retro-style scooters, 50–125 cc
13 in	110/70-13, 130/70-13	Mid-size 125–160 cc scooters
14 in	90/90-14, 100/80-14, 110/70-14, 110/80-14, 120/70-14, 140/70-14	Larger-wheel 125–160 cc scooters and maxi-scooter rears
15 in	120/70-15	Front wheel of many 250–400 cc maxi-scooters
16–17 in	2.25-16, 2.50-16, 2.25-17, 2.50-17	Traditional pedal-style and narrow-tire mopeds

Stand-up electric kick scooters use a different notation, such as 10 × 2.50 or 8½ × 2. In that format the first number is usually the approximate overall tire diameter in inches, not the rim diameter, so it cannot be compared directly with seated scooter sizes.

Scooter tire size conversion chart: inch to metric

An inch scooter tire size converts only approximately to a metric size, and the rim diameter must stay the same. A 3.50-10 can be compared with a 90/90-10 or 100/80-10, never with a 12-inch size. The conversion is approximate for two reasons. Nominal inch widths do not convert exactly to metric widths, and inch sizes do not state an aspect ratio. The pairings below are the ones commonly used in conversion charts. The inch-to-millimetre column is plain arithmetic: 1 in = 25.4 mm.

Inch width	Inch width in mm	Commonly paired metric sizes (same rim)
2.75	69.9 mm	70/90, 80/80
3.00	76.2 mm	80/90, 90/80
3.50	88.9 mm	90/90, 100/80
4.00	101.6 mm	100/90, 110/80

Treat these as starting points for comparison, not guaranteed equivalents. The actual width and diameter of a specific inch or metric tire depend on its construction and on the rim width it is mounted on. The tire manufacturer's published dimensions for that exact product are a better reference.

How do width, aspect ratio and rim diameter change tire size?

Overall tire diameter equals the rim diameter plus two sidewall heights. Each of the three size numbers affects the result:

• Width: at the same aspect ratio, a wider tire also has a taller sidewall, so the overall diameter grows.
• Aspect ratio: at the same width, a lower ratio gives a shorter sidewall and a smaller overall diameter.
• Rim diameter: each inch of rim adds 25.4 mm to the overall diameter. That makes it the largest single step, and it also requires a different wheel.

Steps to calculate sidewall height, diameter and circumference

1. Calculate sidewall height in millimetres: section width (mm) × aspect ratio ÷ 100.
2. Convert rim diameter to millimetres: rim diameter (in) × 25.4.
3. Calculate overall diameter in millimetres: rim diameter (mm) + 2 × sidewall height (mm).
4. Calculate circumference in millimetres: overall diameter (mm) × π (about 3.1416).
5. Compare two sizes by percentage: (new value − old value) ÷ old value × 100.

Worked example: 130/70-13 compared with 140/70-13 and 130/60-13

Start with a 130/70-13 scooter tire. The sidewall height is 130 × 0.70 = 91 mm. The rim is 13 × 25.4 = 330.2 mm. The overall diameter is 330.2 + 2 × 91 = 512.2 mm, and the circumference is about 1,609 mm.

A 140/70-13 keeps the same ratio but is 10 mm wider. Its sidewall is 98 mm, its overall diameter 526.2 mm and its circumference about 1,653 mm. That is 14 mm (about 2.7%) taller than the 130/70-13 in calculated diameter.

A 130/60-13 keeps the width but lowers the ratio. Its sidewall is 78 mm, its overall diameter 486.2 mm and its circumference about 1,527 mm. That is 26 mm (about 5.1%) smaller in calculated diameter.

The percentage change in circumference matches the percentage change in diameter. It roughly equals the change in distance travelled per wheel revolution. If the speedometer takes its reading from the wheel whose tire changes, a larger circumference makes it show less than the true speed by about that percentage, and a smaller one makes it show more.

Calculated geometry chart for common scooter tire sizes

The values below are nominal figures from the formula above, rounded to 0.1 mm. They are not measured dimensions of any specific tire.

Tire size	Sidewall height	Overall diameter	Circumference
90/100-10	90.0 mm	434.0 mm	1,363.5 mm
90/90-10	81.0 mm	416.0 mm	1,306.9 mm
90/90-12	81.0 mm	466.8 mm	1,466.5 mm
110/70-12	77.0 mm	458.8 mm	1,441.4 mm
120/70-12	84.0 mm	472.8 mm	1,485.3 mm
130/70-12	91.0 mm	486.8 mm	1,529.3 mm
110/70-13	77.0 mm	484.2 mm	1,521.2 mm
130/70-13	91.0 mm	512.2 mm	1,609.1 mm
90/90-14	81.0 mm	517.6 mm	1,626.1 mm
100/80-14	80.0 mm	515.6 mm	1,619.8 mm
100/90-14	90.0 mm	535.6 mm	1,682.6 mm
110/70-14	77.0 mm	509.6 mm	1,600.9 mm
110/80-14	88.0 mm	531.6 mm	1,670.1 mm
120/70-14	84.0 mm	523.6 mm	1,644.9 mm
140/70-14	98.0 mm	551.6 mm	1,732.9 mm
120/70-15	84.0 mm	549.0 mm	1,724.7 mm

For an inch size the aspect ratio has to be assumed. If a 3.50-10 is treated as 100% profile, the estimate is an 88.9 mm sidewall and a 431.8 mm overall diameter. That is only an estimate, because real inch-sized tires vary.

Front and rear tire sizes of popular scooters

Many scooters use different front and rear tire sizes, usually a narrower front and a wider rear. Some also use different rim diameters at each end. The stock sizes below are commonly listed for these models. Sizes can change between model years, generations and markets, so the owner's manual or the tire information label on the scooter should be treated as authoritative for a specific vehicle.

Model (generation)	Front tire	Rear tire	Calculated diameter, front / rear
Yamaha NMAX 125/155	110/70-13	130/70-13	484.2 mm / 512.2 mm
Honda PCX 125/160 (2021 onward)	110/70-14	130/70-13	509.6 mm / 512.2 mm
Honda PCX (2018–2020)	100/80-14	120/70-14	515.6 mm / 523.6 mm
Honda PCX (earlier generations)	90/90-14	100/90-14	517.6 mm / 535.6 mm
Honda ADV 150 / ADV 160	110/80-14	130/70-13	531.6 mm / 512.2 mm
Honda ADV 350	120/70-15	140/70-14	549.0 mm / 551.6 mm
Yamaha Aerox 155	110/80-14	140/70-14	531.6 mm / 551.6 mm
Yamaha XMAX 125/250/300	120/70-15	140/70-14	549.0 mm / 551.6 mm
Yamaha Fazzio 125	110/70-12	110/70-12	458.8 mm / 458.8 mm

NMAX tire size front and rear

The Yamaha NMAX is commonly listed with a 110/70-13 front tire and a 130/70-13 rear tire. Both wheels are 13 inches. The rear tire is 20 mm wider, and its calculated overall diameter is 28 mm larger because its 70% sidewall is taller.

PCX tire size front and rear

The Honda PCX tire size depends on model year. The 2021-onward PCX 125/160 is commonly listed with 110/70-14 front and 130/70-13 rear tires. The 2018–2020 generation used 100/80-14 front and 120/70-14 rear. Earlier versions used 90/90-14 front and 100/90-14 rear. The 2021-onward rear tire fits a 13-inch rim, so it cannot be fitted to an older 14-inch PCX rear wheel, even though the calculated diameters are close.

ADV tire size front and rear

The Honda ADV 150 and ADV 160 are commonly listed with a 110/80-14 front tire and a 130/70-13 rear tire. The front's 80% profile gives it a calculated diameter about 20 mm larger than the rear. The larger Honda ADV 350 uses 120/70-15 front and 140/70-14 rear.

Aerox tire size front and rear

The Yamaha Aerox 155 is commonly listed with a 110/80-14 front tire and a 140/70-14 rear tire. Both wheels are 14 inches. The rear tire is 30 mm wider, and its calculated diameter is about 20 mm larger.

XMAX tire size front and rear

The Yamaha XMAX 125/250/300 is commonly listed with a 120/70-15 front tire and a 140/70-14 rear tire. The front uses a larger 15-inch rim and the rear a wider tire on a 14-inch rim, so the calculated overall diameters end up within about 3 mm of each other. Earlier or larger-displacement XMAX versions may use different sizes, so check the model year.

Fazzio tire size front and rear

The Yamaha Fazzio 125 is commonly listed with 110/70-12 tires at both front and rear. The two positions share a size, but a tire marked for front or rear use or with a rotation arrow should still be fitted in the position and direction it is marked for.

Scooter tyre size chart for India

Indian-market scooters mostly use 10-inch and 12-inch wheels, and many 110–125 cc commuter scooters pair a 12-inch front with a 10-inch rear. Common tyre sizes include 90/90-12 at the front and 90/100-10 or 90/90-10 at the rear. Older or basic models may use inch sizes such as 3.50-10. Larger premium scooters sold in India use 13- or 14-inch wheels, as with the Yamaha Aerox 155's 110/80-14 front and 140/70-14 rear. Indian sidewalls follow the same format: width, aspect ratio, rim diameter, then load index and speed symbol. Many also show a ply rating (such as 4PR or 6PR) and TL or TT for tubeless or tube type. A tube-type tyre should not be run tubeless on a rim that is not designed for tubeless use.

What dimensional differences mean and where calculations stop

A calculated tire dimension is a nominal estimate. It is useful for comparing two sizes, but it does not predict a specific tire's real size, and it does not prove the tire fits a vehicle.

Calculated geometry versus actual tire dimensions

Actual width and diameter differ from the calculated values for several reasons:

• Section width is defined on a specific measuring rim. On a wider or narrower rim, the tire's actual width changes.
• Tread depth, tread profile, carcass construction and inflation pressure vary between brands and models.
• Tires grow slightly in use and lose diameter as the tread wears.

Two tires of the same marked size from different makers can measure differently. For exact figures, use the dimensions the tire manufacturer publishes for that product.

Why a similar calculated diameter does not mean compatible fitment

Fitment depends on more than overall diameter:

• Rim diameter: it must match exactly.
• Rim width: it must be within the tire's approved range.
• Clearance: the tire needs room around the bodywork, mudguards, brake components and, on most scooters, the engine and transmission unit that also acts as the rear swingarm.
• Ratings: the load index and speed symbol should be at least those specified for the vehicle.
• Construction: tubeless or tube-type must suit the rim.
• Position: front and rear designations must be followed.

A different size can also change handling, ground clearance, speedometer reading and, on some vehicles, ABS behaviour. Local rules may require the size shown in the vehicle documents.

How to compare a replacement scooter tire size

1. Read the current size, load index and speed symbol from the sidewall, and confirm them in the owner's manual for your model year.
2. Check that the candidate tire has the same rim diameter and is approved for your rim width.
3. Calculate sidewall height, overall diameter and circumference for both sizes, and work out the percentage difference.
4. Confirm that the candidate's load index and speed symbol are at least the specified values.
5. Treat any change from the specified size as a fitment question that the calculation alone cannot answer. Clearance and approval have to be confirmed separately.