What do the numbers in the tire size relate to?
Here's what the letters and numbers on your tires mean. The most basic information that you'll find on a tire's sidewall is related to its size. This is normally written as 185/65R15, for example, though you'll sometimes see "P" (for passenger cars ...
How do you calculate the diameter of a tire?
- Make sure the tire is completely inflated and is mounted on the vehicle.
- Measure the width of the tread of the tire. This is the distance from the tread's inner edge to its outer edge.
- Measure the diameter of the tire. This is the outside width of the tire.
- Measure the height of the tire.
What do the numbers stand for on tire sizes?
What Do Tire Numbers Mean? The letters and tire numbers printed on the tire represent model, width, aspect ratio, construction, wheel diameter, load index, and speed rating. For a better understanding, let’s take the series “P215/65R15 95H” as a reference. Type
Does size of tire make a difference?
Typically, the larger the tire diameter, the wider the tire as well. This allows more of the surface of the tire to be in contact with the road when driving. Let’s say you start off with a 15-inch tire and the dealer upgrades you to the 18-inch. Really, that’s just the size of the rim that fits in the middle of the tire.
What do the 3 numbers mean in tire size?
B: TIRE WIDTH The three-digit number following the letter is the tire's width (from side to side, looking at the tire head on) in millimeters. This may also be referred to as the section width. C: ASPECT RATIO The forward slash separates the tire width number from the two-digit aspect ratio.
What does the 265 70R17 mean?
An arrow points to the numbers 265/70R17 115T on the inner part of the tire sidewall. 265 is the width, 70 is the aspect ratio, R stands for radial, 17 is the wheel diameter and 115T is the load index and speed symbol.
What does 275 mean on a tire?
The numbers in the tire size refer to its width, aspect ratio, and wheel diameter. "275/35R19" means the tire is 275 mm wide, has an aspect ratio (that is, the width divided by the height) of 35%, and fits on a 19" wheel.
What do tire sizes stand for?
The two-digit number after the slash mark in a tire size is the aspect ratio. For example, in a size P215/65 R15 tire, the 65 means that the height is equal to 65% of the tire's width. The bigger the aspect ratio, the bigger the tire's sidewall will be.
What is the difference between 265 70R17 and 265 65R17?
The 265/70R17 is a General Grabber ATX and the 265/65R17 is the stock Hankook. And just for fun, it doesn't look very big compared to a 26x4. 8” bike tire, it's just barely taller!
How tall is a 285 tire?
The sidewall height or "aspect ratio" of a 285/75/R16 tire is 75% of 285mm. Example: 285/75R16 (285 X 75 / 2540 x 2) + 16 = 32.8 inches tall.
How much bigger is a 33 inch tire than a 275?
But we've got you covered. Tires that measure 275/60 R20 are equivalent to the 33-inch.
What does the 75 stand for in 295 75R22 5?
In low profile sizes such as the 295/75R22. 5, 295 is the tread width measured in mm's and 75 is the aspect ratio. In this case the sidewall is a lot narrower than the standard aspect ratio tire size (90 for standard; 75 for the low profile). The smaller this number, the less sidewall area.
How tall is a 295 tire?
295/70R17 tires are 33.3″ tall, have a section width of 11.6″, and fit wheels with a diameter of 17. The circumference is 104.4″ that translates into 607 revolutions per mile.
Can I use 245 tires instead of 235?
The quick answer is yes you can replace 245/50-18 tyres with 235/50-18 but they will have 10mm (0.4 in) smaller overall diameter. Will only slightly effect speedo and odometer - ie speedo will read about 1.5% high.
How wide is a 285 tire?
285/75R18 tires have a diameter of 34.8", a section width of 11.2", and a wheel diameter of 18". The circumference is 109.4" and they have 579 revolutions per mile. Generally they are approved to be mounted on 7.5-9.5" wide wheels.
How wide is a 305 tire?
How Wide Are 305 Tires? Tire width is measured in inches which means that a 305 tire is 305mm wide or approximately 12 inches.
What is the 265 on a tire mean?
265 = Section Width in millimeters (measured at the widest part of the tire from sidewall to sidewall) /60 = Aspect Ratio or section height to width ratio as a percentage. For this example, the side wall is 60% of the section width of the tire (265mm x . 60 = 159mm). Therefore, the sidewall height is 159mm.
What size is a 265 70R17?
265/70R17 tires are 31.6″ tall, have a section width of 10.4″, and fit wheels with a diameter of 17. The circumference is 99.2″ that translates into 638 revolutions per mile. As a rule, they can be mounted on the wheels with 17″ x 7-9″(LT Tires 7-8.5″) rim width.
What is the difference between 225 and 265 tires?
Registered. Not quite that simple,, 225 and 265 are the width, but 75 or 70 is an aspect ratio of the width to the sidewall so a 225/75/16 is 29in tall, a 265/75/16 will be 31.5in tall, and 265/70/16 will be 30.5in tall. (width divide by 25.4 times aspect ratio divide by 100, times 2 plus rim diameter).
What is the meaning of 265 65R17?
265/65R17 tire has a sidewall height of 6.8 inches or 172 mm which is the measurement of tire sidewall from the wheel rim to the top of tire tread. Tire sidewall height or "profile" depends on aspect ratio - lower aspect ratio means lower tire profile.
What does tire size mean?
Tire Size Meaning. There are two ways that tire manufacturers display tire size, inches and metric. To find the tire size meaning in inches is very straight forward. The first number is your overall diameter of the tire. In this example the tire diameter or "height" is 33 inches tall.
How to find tire height?
To get the overall diameter or "height" of the tire you would add the two sidewalls and the diameter of the wheel. In example "B" the last number "17" is the wheel size the tire will fit on. Therefore the sidewall twice would be 8.41 x 2 = 16.82 plus the wheel "17" makes the tire height 16.82 + 17 = 33.82.
What does the second number mean on a tire?
The second number represents the width of the tire. In most cases with inch measurement tires the width will have a .50 decimal after the initial number. In example "A" this reads 12.50, meaning the tire width is 12 and 1/2 inches. The final number simply is the wheel size or "diameter"of the wheel that the tire will fit on.
How many inches is 305mm?
There are 25.4 mm in one inch. To convert 305mm to inches you divide 305mm by 25.4 to get 12". So your width of a 305mm tire is 12 inches. The next number represents the percentage of the width (305mm or 12") that is the sidewall measurement of the tire.
How to read tire size?
There are two ways that tire manufacturers display tire size, inches and metric. How to read tire size in inches is very straight forward. Example A : 33X12.50R15 The first number is your overall diameter of the tire. In this example the tire diameter or "height" is 33 inches tall. The second number represents the width of the tire. In most cases with inch measurement tires the width will have a .50 decimal after the initial number. In example "A" this reads 12.50, meaning the tire width is 12 and 1/2 inches. The final number simply is the wheel size or "diameter" of the wheel that the tire will fit on.
What does the second number mean on a tire?
The second number represents the width of the tire. In most cases with inch measurement tires the width will have a .50 decimal after the initial number. In example "A" this reads 12.50, meaning the tire width is 12 and 1/2 inches.
What is the final number of a tire?
The final number simply is the wheel size or "diameter" of the wheel that the tire will fit on. How to read tire size with a metric measurement is a little more difficult and usually takes a calculator to get exactly right.
What is a LT tire?
The tire is designed to be mounted on an 15 inch wheel diameter. Tire Class : LT. The tire class of this tire size is 'LT' which means it is a Light Truck tire.
How to convert 285mm to inches?
To convert 285mm to inches you divide 285 by 25.4 to get 11.22". So the width of a 285mm tire is 11.22". The next number represents the percentage of the width (285mm or 11.22") that is the sidewall height of the tire. In this example the side wall height of the tire would be 75% of 11.22" which is 8.41" or 214mm.
What is the second number in the size of a tire?
The second number in the size of a metrically sized tire, most often a 60 or 70, is the height of the sidewall expressed as a percentage of the width. This is called the "aspect ratio." People very often get this wrong, thinking it just the height of the sidewall, forgetting that it is a percentage. This small but simple concept is probably the hardest part of understanding tire sizes.
What is the first number on a tire?
The first number in a tire's size, say 225 , is the width of the tire in millimeters. This is pretty straight forward except that in the days of buying tires sized by the inch (remember 31/10.50x15), the first number was the height rather than the width. Back then it was inches, not millimeters.
What are the advantages of radial tires?
There are two main advantages to radial tires. First, the radial cords in the sidewall of the tire allow it to act like a spring, giving flexibility and ride comfort. Secondly, the rigid steel belts reinforce the tread region, giving high mileage and performance.
What size tires are good for a 15 inch rim?
In these two given examples, the tires would be 30 inches tall and 10 1/2 inches wide for a 15 inch rim or 34 inches tall by 9 inches wide for a 16 inch rim.
What is offset on a wheel?
The offset is measured in millimeters and can be one of three types: Zero offset is when the hub mounting surface is even with the centerline of the wheel. Positive offset: the hub mounting surface is toward the front or outside of the rim side.
What is a R tire?
Next, let's discuss the "R.". The "R" is for radial. Because of its advantages, the radial tire has now become the standard design for essentially all automotive tires. Radial-ply tires, more commonly called radial tires, is an automotive tire where the cord plies are arranged at 90 degrees to the direction of travel.
How wide are 225 tires?
The 225 tires are 10 mm wider than the current 215 tires. The other reason to say maybe is that we don't know if the new tires are the same brand as the old tires. Different tire manufacturers seem to measure their tires slightly differently.
What does 55 mean on a tire?
For example, a tire size of P225/55 R15 tire, the 55 means that the height is equal to 55% of the tire’s width.
What is a radial tire?
A radial tire means that the layers run radially across the tire. Numbers 15: This number is the inner diameter in inch, or other words, what size of rims this tire fits on. In our example, this tire says it is a 15-inch tire, which means that we need 15″ rims.
What is load index?
The Load Index describes the total max weight that the tire can handle when it is fully inflated. The higher the load index rating, the more weight it can handle. You need a tire load index chart to see the exact numbers.
What does the letter P mean on a tire?
Letter P: The first letter at the beginning tells us which type of tire we have. In this case, we have a “P”, which means that it is a Passenger car tire. This means that it is made to a certain standard in the USA. You can also find the letters “LT” which means that they are designed for light trucks. If you find no number at all here, it means that the tires are made in Europe. Euro-Metric tires do also have different load capacities.
Is Tire Size Important?
The tires must fit your vehicle perfectly for proper operation. The first issue with improperly sized tires is the appearance. When you put on tires that are too small or too large for your vehicle, it isn’t going to look right.
What are the sizes of tires?
Tires usually come in the following widths (in inches): 8, 10, 12, 13, 14, 15, 17, 18, 19, 20, 22, 23, 24, 26, and 28. Tires in these sizes are typically found on most passenger cars, light-duty light trucks, SUVs, minivans, and vans. Tires with a rim diameter measured in inches are called "inch rim" sizes.
How wide is a tire?
In the example above, the tires width, measured from the widest point of the inner sidewall to the widest point of the outer sidewall when properly mounted, is 225 millimeters. The section width can be converted to inches by dividing the width in millimeters by 25.4 like so: (225 millimeters) / (25.4 mm/in) = 8.86 inches.
What is a metric tire?
Metric tires, also known as Euro-Metric tires because the sizing originated in Europe, don't have a letter designation. Euro-Metric sizes are equivalent to P-Metric sizes in dimensions, but Euro-Metric sizes have subtle differences in their load-carrying ratings and capabilities. Euro-Metric tires are usually found on European cars, but they're also used frequently used on SUVs and vans.
What is a P tire?
P-Metric tires are the most common type of tire. The P stands for passenger vehicle, meaning that these tires are designed for use on passenger vehicles like cars, minivans, light-duty pickup trucks (? ton or ? ton capacity), and SUVs.
What does the 2 digit number on a tire tell you?
The two-digit number that usually follows the tire's section width tells us the aspect ratio, or tire profile measurement.
What size tires are used for heavy cargo?
Wide base tires are also designed to carry heavy cargo loads and/or tow trailers on a wheel rim with a diameter of 16.5 inches.
What does a T mean on a tire?
If the tire size begins with a T, it means that the tire is a temporary spare. Also known as mini spares or space savers, temporary spares are designed for short-term use until the regular tire is repaired or replaced.
What is the section width of a tire?
A metric tire’s section width is measured in millimeters. This measurement is taken from sidewall to sidewall. In this example, the section width of the tire is 205mm .
What does the R in a tire mean?
The “R” in this example indicates radial tire construction.
How many plies does a tire have?
If there is no letter, the tire has the standard 4 plies. A “C” indicates 6 plies, a “D” indicates 8 plies, and an “E” indicates 10 plies. The higher the number of plies in a tire, the stronger the tire is and the more air pressure the tire can safely hold.
What do the letters on the side of a tire mean?
These letters and numbers tell you the tire size, type of tire and the safety standards. We will teach you how to read your tires below.
What does DOT mean on tires?
DOT. The “DOT” marking indicates that the tire meets or exceeds the U.S. Department of Transportation’s safety standard for tires. Manufacturer Plant Code – “CC”. The first two letters following the DOT marking are codes to identify the manufacturer of the tire and the manufacturing plant. Tire Size – “9L”.
What is the maximum load on a tire?
Maximum Load Limit – “635 kg [1400 lbs]”#N#This indicates the tire’s maximum load-carrying capabilities when the tire is inflated to its maximum inflation pressure, as indicated on the sidewall. Max load is based on standards set by the National Highway Traffic Safety Administration (NHTSA)
What does the letter P mean in a tire?
The first character (s) in a tire size designate the tire’s class. In this example, “P” indicates that the tire is a passenger car tire. An “LT” before the tire size designates a light truck tire, and no letter before the size indicates that it is a European metric tire.
What is the width of a tire?
The width of the tire can vary from 125 mm to 335 mm. The width always goes in steps of 10 mm. Tire sizes range from 125-135-145-155-165-175-185-195-205-215-225-235, etc. The tire width of the average middle class car is 205 mm wide.
What are the factors that determine tire size?
The tire size is made up of 7 factors, namely the width of the tire, the height of the tire, the type of tire, the rim size, and the load capacity and speed index. Tire Size Chart: Tire Dimensions explained.
How to calculate tire height?
Height of car tire In the tire size, the number that comes after the width of the tire (2nd part) is the height of the tire which is a percentage of the width of the tire. In the example above that number is 55. This means that the height of the tire is 55% of the width of the tire, which in this example is 195 mm. The calculation is easy by multiplying the width of the tire (195) by 0.55. You then arrive at 107.25 mm
What is the direction of rotation of a tire?
The direction of tire rotation: What is independent of the tire size is the direction of rotation. Some tires have an arrow on the side of the tire. This arrow indicates the direction of rotation / running direction of the tire. The arrow must always point towards the front of the car. Tires with a V profile have at least an arrow and therefore also a running direction. Pay attention to this when mounting the tire or when changing a wheel. The steering and driving behavior can be directly influenced by incorrect mounting.
What is rim size?
The rim size is the size of the rim around which the tire fits exactly. This is the inner size of the car tire and the outer size of the rim. Rim size is almost always given in inches.
What does R stand for in tires?
The tire type is in almost all cases indicated with the letter R. R stands for Radial . Radial explains how the tire was made. With a Radial tire, steel cord plies are applied perpendicular to the direction of rotation, so in the width of the tire. This makes the tire very flexible and maintains contact with the road surface when cornering. The counterpart of the Radial tire is the Diagonal tire. With the Diagonal band, the cord layers are placed diagonally over the band.
Why are rims bigger?
A larger rim fits wider tires which are necessary for better road holding and can also handle a higher weight. Nowadays, cars are increasingly equipped with larger rims (15 ″ / 16 ″ / 17 “) because this is not only more beautiful and sporty, but also because the tires are more common, which makes them cheaper.
What does R mean on a tire?
R — This indicates your tire's design, which in this case is radial. Radial is the most common tire design on the market today, but you might see one of these instead:
What does load index mean on a tire?
Load index is a code that indicates how many pounds a tire can carry at a given inflation level. In this instance, a load index of 92 would mean that tire is capable of carrying 1,389 pounds at 36 psi inflation. H — This indicates the speed rating. Speed rating is the highest speed a tire can safely handle, determined through lab testing.
What is a LT tire?
LT is for a light truck. ST is for a special trailer. T is for temporary, usually indicating a spare tire. European-standard tires won't have a prefix letter at all. 205 — This is the section width of the tread, from sidewall to sidewall. In this case, the tire's section width is 205 millimeters.
What is the maximum speed of a tire?
Speed rating is the highest speed a tire can safely handle, determined through lab testing. In this case, an H-rated tire is good for speeds up to 130 mph. Code. Maximum Speed (mph) Q. 100.
Can you tell if a tire is a tire?
Your tires can tell you a lot — if you know how to read what they have to say. Many years ago, the tire industry established a set of standards for the information that's embossed on the sidewall of tires.
