To simplify the determination of tire size, a special tire calculator was developed, allowing the user to do without the need to decipher the digital values ​​​​on the side surfaces of the rubber. Using such a calculator, the difference in tire sizes, profile height and other parameters are determined. In addition, such a calculator allows you to obtain other related information, for example, on deviations in the speedometer, changes in ground clearance, and so on.

Purpose of the visual tire calculator

A visual calculator allows every car owner to easily determine the tire size and width of the required rims. With its help, it is possible to determine the diameter of the wheels, the error of the speedometers, the increase in the road track and changes in the clearance under the bottom of the car. Through tire calculator extremely easy to define optimal size, suitable for a specific car model. The built-in size conversion system allows you to instantly transform values ​​from the inch system to the meter system and vice versa.

It is advisable to take advantage of the potential of the calculator in cases where the car owner switches to using tires and wheels of a different size from the original one. It allows you to visually determine the main dimensions and then model them for the selected car. In turn, it is impossible to select tires using it, since initially it does not provide for division by manufacturer.

Selection and comparison of tires according to calculator 2.0

In the case of installing new wheels and tires of a different size, based on the data received from the calculator, it is advisable to additionally carry out a number of measurements. It is advisable to determine the distance by inside between the wheel and the suspension, as well as from the tread to the shock absorber cup. In addition, you will need to measure the distance between the tread, fender and steering rods.

In turn, when choosing new tires, it is necessary to proceed from the feasibility of a slight deviation in the geometric dimensions of the new tires from those previously used. A significant size will cause instability in the movement of the car.

Each car is initially created to certain parameters and dimensions. This fully applies to the permissible size of the wheels and tires used. Accordingly, the selected tire models must be within the established limits. The use of a tire calculator allows you to simplify the selection process as much as possible depending on the specific vehicle.

Russians have to regularly deal with replacing tires, primarily seasonal ones. The most simple solution In such a situation, it is better to use rubber of a similar size. If the tire size is maintained, the wheel will also retain its original dimensions.

In cases where tires of a different size are selected, the selection of appropriate disks is required to obtain a wheel with the required dimensions. Moreover, due to the change standard sizes tires have the ability to control the driving characteristics of the car, giving additional softness or hardness. The higher the profile used, the softer the car feels on the road. As the profile decreases, rigidity increases, and narrow tires give more grip on snowy surfaces, so they look more advantageous on winter roads.

At the same time, when selecting the size of tires and wheels, you must adhere to permissible sizes. For example, tires that are too wide will touch wheel arches, rubbing them, and intensively wearing out on their own. It is also worth taking into account the fact that changing the size of the wheels affects the operation of the speedometer, in particular the magnitude of the error.

From the outside it may seem that the variety of available configurations greatly complicates the calculations, but the tire calculator greatly simplifies the selection process using 3D modeling. Correct selection tires, this is not only necessary safety, but also optimization road possibilities car. At the same time, the presence of a metric and inch size system allows you to work without problems with both American and European standard sizes.

Do you want to choose a tire for your car, but are not well versed in tire labeling? No problem! In this section, we will help you figure out what tire parameters are, what they mean, and which tire is suitable for your car.

Select tires / tire catalog

Decoding tire markings.

195/65 R15 91 T XL

195 is the width of the tire in mm.

65 - Proportionality, i.e. ratio of profile height to width. In our case it is 65%. Simply put, with the same width, the larger this indicator, the higher the tire will be and vice versa. Usually this value is simply called “profile”.

Since the tire profile is a relative value, it is important to take into account when selecting tires that if instead of size 195/65 R15 you want to install tires with size 205/65 R15, then not only the width of the tire will increase, but also the height! Which is unacceptable in most cases! (except for cases when both of these standard sizes are indicated in the car’s operating book). Accurate change data external dimensions You can calculate the wheels using a special tire calculator.

If this ratio is not specified (for example, 185/R14C), then it is equal to 80-82% and the tire is called full-profile. Reinforced tires with this marking are usually used on minibuses and light trucks, where a large maximum load on the wheel is very important.

R- means a tire with a radial cord (in fact, now almost all tires are made this way).

Many people mistakenly believe that R- means radius of the tire, but this is precisely the radial design of the tire. There is also a diagonal design (indicated by the letter D), but recently it is practically not produced, since it performance characteristics noticeably worse.

15 - wheel (disk) diameter in inches. (It’s the diameter, not the radius! This is also a common mistake). This is the “fitting” diameter of the tire on the disk, i.e. This is the inner size of the tire or the outer size of the rim.

91 - load index. This is the level of maximum permissible load on one wheel. For passenger cars it is usually done with a reserve and is not a decisive value when choosing tires (in our case, IN - 91 - 670 kg.). For minibuses and small trucks, this parameter is very important and must be observed.

Tire load index table:

T- tire speed index. The larger it is, the higher the speed you can drive on a given tire (in our case IS - N - up to 210 km/h). Speaking about the tire speed index, I would like to note that with this parameter the tire manufacturer guarantees normal operation of the tire when the car is constantly moving at the specified speed for several hours.

Speed ​​index table:

American tire markings:

There are two different markings American tires. The first one is very similar to the European one, only the letters “P” are placed in front of the standard size (Passanger - for passenger car) or “LT” (Light Truck - light truck). For example: P 195/60 R 14 or LT 235/75 R15. And another tire marking, which is fundamentally different from the European one.

For example: 31x10.5 R15(corresponds to European size 265/75 R15)

31 - outer diameter of the tire in inches.
10.5 - tire width in inches.
R- a tire with a radial design (older tire models had a diagonal design).
15 - inner diameter of the tire in inches.

Generally speaking, apart from the unusual inches for us, the American tire markings are logical and more understandable, unlike the European ones, where the tire profile height is not constant and depends on the width of the tire. And here everything is simple with decoding: the first number of the standard size is the outer diameter, the second is the width, the third is the inner diameter.

Additional information indicated in the markings on the sidewall of the tire:

XL or Extra Load - reinforced tire, the load index of which is 3 units higher than that of conventional tires of the same size. In other words, if a given tire has a load index of 91 marked XL or Extra Load, this means that with this index, the tire is capable of withstanding maximum load 670 kg instead of 615 kg (see table of tire load indexes).

M+S or M&S tire marking (Mud + Snow) - mud plus snow and means that the tires are all-season or winter. On many summer tires for SUVs, M&S is indicated. However, these tires cannot be used in winter, because... winter tires have a completely different rubber composition and tread pattern, and the M&S badge indicates good cross-country ability of the tire.

All Season or AS all season tires. Aw (Any Weather) - Any weather.

Pictogram * (snowflake)- rubber is intended for use in harsh conditions winter conditions. If there is no this marking on the sidewall of the tire, then this tire is intended for use only in summer conditions.

Aquatred, Aquacontact, Rain, Water, Aqua or pictogram (umbrella)- special rain tires.

Outside and Inside; asymmetrical tires, i.e. It is important not to confuse which side is external and which internal. When installing, the inscription Outside should be on the outside of the car, and Inside should be on the inside.

R.S.C.(RunFlat System Component) - RunFlat tires are tires on which you can continue driving a car at a speed of no more than 80 km/h with a COMPLETE loss of pressure in the tire (due to a puncture or cut). On these tires, depending on the manufacturer's recommendations, you can drive from 50 to 150 km. Different tire manufacturers use different designations for RSC technology. For example: Bridgestone RFT, Continental SSR, Goodyear RunOnFlat, Nokian Run Flat, Michelin ZP, etc.

Rotation or arrow, this marking on the sidewall of the tire indicates a directional tire. When installing a tire, you must strictly observe the direction of rotation of the wheel indicated by the arrow.

Tubeless- tubeless tire. If this inscription is missing, the tire can only be used with a tube. Tube Type - means that this tire must be used only with a tube.

Max Pressure; maximum permissible tire pressure. Max Load - maximum permissible load for each car wheel, in kg.

Reinforced or the letters RF in the standard size (for example 195/70 R15RF) mean that this is a reinforced tire (6 layers). The letter C at the end of the size (for example 195/70 R15C) indicates a truck tire (8 plies).

Radial - this marking on the tire in the standard size means that it is a tire of radial design. Steel means that the tire has a metal cord in its construction.

Letter E(in a circle) - the tire meets the European requirements of ECE (Economic Commission for Europe). DOT (Department of Transportation - US Department of Transportation) - American quality standard.

Temperature A, B or C heat resistance of tires at high speeds on a test bench (A is the best indicator).

Traction A, B or C- the ability of the tire to brake on a wet road surface.

Treadwear; relative expected mileage compared to special standard test USA.

TWI (Tread Wear Indication)- indicators of tire tread wear indicators. The marking on the TWI wheel may also include an arrow. The indicators are located evenly in eight or six places around the entire circumference of the tire and indicate the minimum permissible tread depth. The wear indicator is made in the form of a protrusion with a height of 1.6 mm (the minimum tread size for light cars) and is located in the tread recess (usually in the drainage grooves).

DOT- Manufacturer's encoded address, tire size code, certificate, production date (week/year).

Good afternoon, dear readers. Today I want to immediately answer many questions related to wheel tire sizes. Many of my readers do not understand what they mean and why they are needed at all! Today I will try to explain in simple and understandable language what tire sizes on cars mean...

Wheel tire sizes contain a lot of useful information, you just need to be able to read it. Without this information, you will not be able to choose the right tires for your car; they simply will not fit in size. Although now the bodies of many brands have special plates with recommendations, you just read them and go to the store to buy the same ones. However, such signs are not always available and you need to determine the tire dimensions yourself! A small clarification, I will only talk about overall dimensions, there have already been many articles about other characteristics, the links will definitely be below.

I will tell you about my winter wheels, KAMA EURO 519, as an example; it should be noted that they are in no way inferior to their foreign counterparts. An informative read.

To begin with, the overall dimensions

My wheel size is R16 205/55 , these are the so-called overall dimensions. Rubber is considered low profile (more details).

The notorious letter R

Many people mistakenly think (to be honest, I thought so too) that the first english letter R stands for the abbreviation RADIUS! But that's not true! The letter R means radial tire, read the article -. This is a method of arranging rubber and metal cord during production. Of course, you can also see the letter D in front (diagonal), but such a designation is now really rare. In fact, this letter has nothing to do with size. Let's move on...

Disc diameter

The second number (in this case we have 16) indicates the diameter of the hole in the rubber, or which disc this rubber can be put on. We have 16, which means it’s 16 inches! Remember that this size is always indicated in inches (1 inch = 25.4 mm). If we calculate our size, it turns out - 16 X 25.4 mm = 406.4 mm. The disc cannot be larger or smaller than the diameter of the wheel; you simply won’t fit it. That is, if the tires are 16 (406.4 mm), then the disk should be 16 (406.4 mm).

Width

A large number almost always characterizes the width. In this case, this figure is 205. It is measured in millimeters, that is, the width of my wheel is 205 mm. The wider the rubber, the wider the track it has, which increases cross-country ability and traction.

Cord height

This is a smaller number that is applied through the fraction. In my case it is 55, measured as a percentage of the width (from the larger number). What does it mean? To find the height (in my case) you need to calculate 55% of 205 mm. Thus it turns out:

205 X 0.55 (55%) = 112.75 mm

This is the cord height of our rubber, also an important indicator, see the figure.

Overall wheel height

Let's calculate the total height of my wheel. What happens.

Rubber cord 112.75 X 2 (since the height is on both sides, top and bottom) = 225.5 mm

For a 16-inch drive = 406.4

Total - 406.4 + 225.5 = 631.9

Thus, my wheel is a little more than half a meter high, namely 0.631 meters

Let's look at the most common tires that are used by most cars, there are three of them - R13, R14 and R15

Tire sizesR13

The most common of all isR13175/70 these are installed on many models domestic VAZ(although it is leaving now).

What happens:

R13 – diameter 13 inches (multiply by 25.4) = 330.2 mm

Width 175

Height - 70% of 175 = 122.5

Total - (122.5 X 2) + 330.2 = 574.2 mm

Tire sizesR14

One of the most common ones isR14175/65 are also installed on domestic VAZ models of more recent years of production, such as Priora, Kalina, Granta, as well as on some inexpensive (folk) foreign cars - for example Renault Logan, Kia Rio, Hyundai Solaris etc.

What happens:

R14 – diameter 14 inches (multiply by 25.4) = 355.6 mm

Width - 175

Height – 65% of 175 = 113.75

Overall dimensions – (113.75 X 2) + 355.6 mm = 583.1 mm

Tire sizesR15

The most common example is -R15 195/65, installed on many foreign cars of the (popular) class, but in high trim levels.

What happens:

R15 – diameter 15 inches (multiply by 25.4) = 381 mm

Width 195

Height – 65% of 195 = 126.75

Total – (126.75 X 2) + 381 = 634.5 mm

As you can see, it is not that difficult to calculate the tire size.

Of course there is another one on the wheel useful information, I already wrote articles about her below. I’ll list them point by point for you, it’s useful and interesting to read:

In general, read the section - there is much more information there. As you can see, all this information can be read from a tire, sometimes you can’t even believe it!

When selecting new wheels for a car, the question often arises: should I get larger or smaller wheels, or for the purpose of improvement? appearance cars or cheaper purchases of tires and wheels. But the most important question arises: will the wheels be suitable for my car and how its characteristics will change. You can find out whether the wheels will fit on the gas tank cap or the side pillar of the car (photo 1). Or find your car in our directory of wheel applicability for cars and see the tires recommended by the factory. But it often happens that you can supply other tires that are not officially approved by the factory.

In this case, the main thing is to understand how the speedometer indicators will change, i.e. the speed of the car, since the outer radius of the wheel will change. The clearance will also change ( ground clearance). It is not recommended to go beyond the factory tire values ​​by more than 2-3%. The vehicle's handling and behavior, gas mileage, and actual vehicle speed may change.

Tire calculator - size comparison

Our tire calculator will show you visual differences in tire diameter, profile, radius, ground clearance and tire width. The dotted lines indicate the difference in size. At the top you can see a visual representation of the old tire (original size), and at the bottom you can see a visual representation of the new tire. Just as you noticed, the tire can be seen in the side and frontal projections. You can copy the page address and show it to other people and they will see the same comparison as you see.

But how to understand all these values ​​and the difference in %? For this purpose, we created a tire calculator; it will help you understand the change in all the necessary characteristics and will show the difference in % between the old and new tire and even visually display what the old and new size wheel will look like. You just need to enter the tire width, profile and wheel radius. Usually they are displayed in this form - 195\65 R15 (photo 2).

How to use the online tire calculator?

Our online tire calculator is very easy to use. In the upper left corner of the site, there are fields for selecting the tire size. In the top row you need to indicate the size of your original factory tire (or the tires currently installed on your car). These values ​​are written on the tire profile (sidewall). In the first list you need to select the tire width - it is indicated in millimeters. The second list is the percentage of the profile height to the tire width. The third list is the diameter of the disk in inches (commonly called radius).

In the bottom row you need to indicate the size of the new tires. Tires that you are going to install on your car or have already purchased. After that, click "Calculate". Our tire calculator will calculate the differences between the old and new tire and display them in a table and picture. Namely: diameter, width, circumference, tire profile height, number of revolutions per kilometer and change in vehicle clearance. The first columns of the table will show the parameters for old and new tires, the following columns will show the difference in mm and percentage difference between them.

There is a speedometer at the bottom of the tire calculator for visual comparison speed of the old and new tire. Under the speedometer, you can increase and decrease the speed and see the changes in the speed difference between the old and new tire.

Be careful!

Be careful on the road and follow the manufacturer's recommendations. The reverse side of the installation is not standard sizes tires, there is a risk of losing insurance in case of an accident, failure to pass a state technical inspection of the car, since the installation of tires not approved by the factory is considered a change in the design of the vehicle.

When choosing car tires, it is important to remember that great value The tire size corresponds to the wheel size. Everything is clear with the diameter - a 15’’ diameter tire must be put on a disk with a diameter of 15’’. Confusion usually arises with the width of the tire and rim. Their discrepancy can lead to a number of completely undesirable consequences associated with the operation of tires. The contact patch may become irregular, causing increased tire wear, poor handling and ride quality auto. In order not to make a mistake with your choice, use the correspondence table.

You can also do the calculation yourself. To do this, consider an example for a tire with a width of 215 mm and a diameter of 16.

1) Convert the tire width into cm: 215 mm = 21.5 cm

2) Convert the resulting value into inches: 1 cm = 2.54 inches, divide 21.5 by 2.54, get 8, 46 - round to 8.5

3) We take 25-30% of the obtained value, in our case: 2.38

4) Subtract the resulting number from the tire width and round to the nearest tenth 8.5 - 2.38 = 6.1

5) The rim width of the disc should be 6.1 inches or 155 mm.

For discs with a diameter up to 14 inches inclusive, an error of 0.5 to 1 inch is possible.

For discs with a diameter of 15 inches inclusive, the permissible error is 1.5 inches.

As a calculation, it is better to calculate the permissible value interval, namely, calculate 25% and 30%, where 25% will be the maximum and 30% the minimum width of the disk rim.

Correspondence table for tires and wheels for passenger cars

Ø disk	Tire size	Rim width (in inches)
		Minimum	Recomm.		Max.
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