If you are thinking of changing your car tyre size or are planning on buying a new wheel/tyre combination then you can use the flash tool below for a visual tyre size comparison of your stock wheel and tyre size versus your new wheel and tyre combination.
Got a comment or question regarding the current version of the tyre size calculator? Click here to leave a comment or ask a question.
Vesion 2 of the tyre size calculator is in development, if there’s anything you’d like to see in version 2 then please feel free to leave a comment here: Tyre Size Calculator V2: Wishlist.
Why is this important?
Matching the combined wheel and tyre diameter is important as it will ensure your ride height and speedometer readings don’t change drastically. An example of this would be fitting 17″ wheels to a car that has 14″ wheels as standard, there are three main consequences:
- the ride height will change, the car body will be further from the ground.
- the top speed will increase slightly and the speedometer will under read.
- the car will accelerate slower.
Read on to see the reason for this in detail.
Tyre Size Guide
Ride Height
Take the default example in the flash tyre size calculator above, here we have a stock tyre size of 165/55R14 and a new tyre size of 215/45R17. There is a total difference of 8.82cm in the two wheel and tyre diameters, if we divide this by two we get a difference in radius of 4.41cm. If we ignore tyre pressures and the effects of adding larger, wider wheels to suspension geometry; then this is roughly how much higher the car will be from the ground.
Speedometer
Then there’s the speedometer, a cars speed reading is usually taken from the transmission and is set based on a number of predefined constants. When you change your wheel and tyre combination you are taking one of these constants and making it variable. The speedometer does not know the new value and so continues to read based on the original wheel & tyre size. If you look at the above default example again you will see that with a 215/45R17 wheel and tyre combination there is a difference of 16.4% in the speedometer reading over the stock setup. As you can see, at 60mph your speedometer should actually be reading 69.9mph!
Acceleration
If we fall back to the default example again, the 215/45R17 wheel and tyre combination has a larger overall diameter by 8.82cm. A larger diameter has a greater rotational inertia which requires more energy to accelerate. Or in other words: the bigger the wheel, the slower the acceleration.
It should be noted that putting a bigger wheel and tyre combination on your car does not reduce your cars power. Your cars power remains the same; however it takes more force to turn your car’s wheels resulting in slower acceleration.
Tyre Width Equivalency Table
You may also find the following table of recommended tyre widths for given rim widths useful when changing your tyre width.
Rim width | Min tyre width | Ideal tyre width | Max tyre width |
|---|---|---|---|
5 .0 inches | 155 mm | 165 ou 175 mm | 185 mm |
5.5 inches | 165 mm | 175 ou 185 mm | 195 mm |
6.0 inches | 175 mm | 185 ou 195 mm | 205 mm |
6.5 inches | 185 mm | 195 ou 205 mm | 215 mm |
7.0 inches | 195 mm | 205 ou 215 mm | 225 mm |
7.5 inches | 205 mm | 215 ou 225 mm | 235 mm |
8.0 inches | 215 mm | 225 ou 235 mm | 245 mm |
8.5 inches | 225 mm | 235 ou 245 mm | 255 mm |
9,0 inches | 235 mm | 245 ou 255 mm | 265 mm |
9.5 inches | 245 mm | 255 ou 265 mm | 275 mm |
10.0 inches | 255 mm | 265 or 275 mm | 285 mm |
10.5 inches | 265 mm | 275 or 285 mm | 295 mm |
11.0 inches | 275 mm | 285 or 295 mm | 305 mm |
11.5 inches | 285 mm | 295 or 305 mm | 315 mm |
12.0 inches | 295 mm | 305 or 315 mm | 325 mm |
12.5 inches | 305 mm | 315 or 325 mm | 335 mm |
can i use michelin 195/60 r15 tires on a Mazda 2 with 185/55 r15 tires
My 2012 Suzuki Swift has 185/55 16 standard alloy wheels. I wish to fit 225/40 17 wheels. Will they fit or be too wide and scrape?
hi everybody,
the Specs of new reconditioned japan car suzuki kei modle 2008 660cc
i have installed my new tyres size 175 R13 instead of 155 R13.
current consumption of fuel is about 11km/liter.
is there any effect on fuel consumption due to changing the tyres size
Hey, i’ve got a pug 306 with 175 65 R15 wheel tyre combo, i’ve just been given 4 wheels with 185 65 R15 tyres, will these 2 sizes interchange safely?
Hi. I’m just wondering why is the actual width of 265/50 R20 is different from 265/70 R17 even if it got the same width size of 265? And also, why does the 265/70 R17 fit a rim of 17 x 7.5 wherein the given table above indicates the maximum width is 235? Thanks..
hi, i have a 205/65 r 15 in my skoda octy. can i change these to 205/55 r18.as i have bought mew 18” alloy wheels that leaves me with no other option…..please anyone guide me throught this…regards.
what knd of calculator is this?, the width ofthe tyre affecting the sidewall AND the speedo rating…. the width across the face of the tyre DOES NOT affect either the speedo rating OR the width of the sidewall, who wrote this calcualtor?, the only things that affect the speedo are the size of the tyre and the sidewall profile as in (???,50,zr17)or just 17. you could have a tyre 95,60,21 (as found on some vintage cars) if you change that for 125,60,21 speedo is not affected as the profile and diameter are the same. please write one that does not mislead people.
The profile is a ratio of the tyres width, so obviously the width will affect both the speedo and the height of the tyre.
Hello,
I have Opel Corsa b 1.0 12v of year 2000 with tyre 165/70×13. Can I change for 165/65×14? The new fuel consumption will be greater?
Thanks in advance!
Will 19 inch rims and tyres fit on a 2012 polo. If so wat size tyres will I need
Doubt it very much mate, I have a MR2 Roadster, originally had 15`s on with inches of space in the arches, took the arch cards out, put 17`s on but they rub bad on 215/45/17 so gotta opt for a 205/35/17, bit of arch work (Grabs the grinder
) and I may just get away with it. Ive found that with smaller cars 15`s are a better all rounder in terms of looks and handling. 17`s really should be your max.
how can changing from 15 inch wheel to an 16 inch affect on golf 4 ???
hi
i have Golf 2005 my tires is 195/65/15 can i use tires 205/55/17 ??
195 / 55 x 17 would be a better match
I am making a tumbler type car using a fiero . I need to know how I would convert my wheels from a stock 14″ to an 18″ or 20″ daully rim.
m driving honda jazz/fit and the stock wheels are 175/65/r15 and rim width is 5.5 inch… i want to fit wider tires without changing the factory rims. tire width equivalency table says that i can fit upto 195 mm wide tire.. should i go for 195/55 tires or 185/60 tires ? i dont want tires bulging out of the rims..
either will be fine… 195/55 are likely to be cheaper and easier to get than 185/60
Hello
i am searching alot on internet about tires and rims, but i think that i am finally on a right place. I have vw polo 1.2, and it has 175/70 R14 84T . i am planing to put some 17′ rims. is this okay? and what tires size is optimal to put on that rims? i would be really thankful for answering..
cheers
195 / 45 on a 17 Inch rim will be a pretty close match for the speedo calibration
currently i am using 215x60x16, my car is a toyota camry 2010 model LE. i will be switching to an 18″ rim with an ideal tire width of 235. i would appreciate if i know what series of tire should i use without it been rub on the car when full load of 5 passenger example 45, 50, 55 or even 60 series. i like my car to be higher and not low like road hugging.
stepping upto a 18 inch rim with a car taking 4 or 5 passengers will give you a shockingly harsh ride
HARSHIT,i purchased new swift ldi with company fitted tyres size 165/80R14.i wants alloys wheels in my car for sutable tyre sizes with no effects on milage(average).please suggest me.
195/55/r15 best size available ..
My original wheels were 165R13-8PRLT but it isn’t listed on the above list any suggestions of how to compare diameters because I am currently running on 215/65 R16
i have bought 19″ / 9/1/2J alloys WHAT SIZE TYRES DO I NEED TO FIT THESE ALLOYS
I have 265 70 16 tyres on my Mitsubishi L200 and assume they are 7j rims as this is the spec. I want to get some new tyres and have been offered 205 80 R16. Will I be able to put them on these rims? according to the way i’m reading the chart here it says they are to narrow.
The standard tyres for the latest L200s are:
205 80/R16
245 65/R17
So you have been given the correct size for a standard 16″ rim.
i think the size calculator is wrong..
let me give u an example-
suppose rim size = 15 inch (381mm) and tire size is 195*55/r15
so the sidewall would be 107.25mm (195*55/100)therefore total
diameter = 488.25 mm but the visual tyre size calculator says
it would be 59.55 cm that is 595mm. please correct me if i am wrong !
@singh you’re calculations are almost right, however you need to multiply your sidewall height figure by two: 107.25 x 2 = 214.50 and then add this to the rim diameter.
The sidewall height figure applies to both the top and bottom as the tyre wraps the wheel…
Hi, my car is nissan sunny and the Stock Tyre Size is 15/185/65 and I want to change and Recommend the New tyre size is 195 / 60 R15 .Could you plz suggest me the new tyre sizes is Correct or no . if no what is the correct Size .
thanks,
I have a 2011 Chevy Silverado 1500 4×4. Stock tires are 265/70 R17. I want to know if 275/75 R17 will fit with a 1 inch leveling kit on the front.
Hi, my OEM recommended tyre size is 165 / 55 R14 but unfortunately, this tyre size is not available in my country. Could you plz suggest me the tyre sizes with minimum difference with the original one’s in rim size R13 and R15
Regards
use the very well crafted visual tyre calculator yourself – it’s up there ^^…
Hi
Can I change my BMW 745i 245/55R17 W102 to 245/45R17′s ?? as there is a huge price difference.
Many Thanks
Rich Wood
Hi. I have a 2009 vw polo 1.4tdi with 195/55 r15. I want to put 195/65 r15 on but the advice on this and other sites suggests this would be a bad idea. Would changing to 65 r15s have a dramatic affect on acceleration and subsequently the mpg? would I be better off with manufacturers recommended size?
cheers bruce.
hi ihave ml350 4matic and have same stock size 19in wheels and iam planing to put wald 20x9front and 20x10rear what tire should i put in honor to read my tpms and esp thanks
Hi, what a useful tool. Only nit picking! you mean rolling circumference, not radius as illustrated don’t you? 3.14159 x dia, so for each revolution of the wheel the vehicle will travel that circumferential length / distance and hence the effect on the speedo reading.
All the best
MG
the caculator tells the diff. in the speed at 30 and 60, but how do u know how it effects the odometer and the fuel mileage readout on the dash?
Hi there,i am in doubt-on my SUV oem tires are 265/60R18,could i put winter 245/65 R18 on it.Rims are 8×18 ET53,vehicle Mercedes GL320cdi
Thank’s in advance
I have a 2004 Jeep Grand Cherokee and currently have 225/75/16 tires installed. I was giving a a complete set of Blizzak but their size are
235/60/16 it wider and about 1″ shorter can I use these tires on my truck or will is throw everything off?
Thanks for your help.
By the way the tires giving to me are brand new haven’t even seen snow yet
what size of tyre do i put on a 2002 Audi A6 1.9 TDi saloon
open the fuel filler cap – there’s a sticker on it… or read the manual… there’s a massive section on appropriate tyre / wheel combinations
One of the opening statements about wheel sizes and speedometer readings seems to be incorrect. Take the Rover 800, these can be fitted with 14″, 15″, 16″ or 17″ wheels and tyres. As the wheel size increases the tyres height decreases, simple!
Surely there is an error with the coding for your tyre size calculator app. Plug in different tyre widths for a wheel with the same rim radius and profile (size) and according to your widget the rolling radius changes – and by considerable amounts. Eh?!
Of course it does. The profile indicates the tyre wall height as a % of the width, so increasing the width but leaving the profile increases the diameter and therefore the circumference, and vice versa.
Yup, that’s because the tyre profile (35, 45, 50 and so on) is a certain proportion of the tyre width (235, 245, 255 etc). So the same 19″ rim could have different width tyres on it.
20% (a purely hypothetical figure) of 255 is more than 20% of 235. That means that the tyre wall on a 255/35 is higher than on a 255/35. Same profile but the height of the wall, and therefore the diameter of the tyre and the rolling radius is therefore greater.
Hi can i change my 245/50 R18 tyres to, 245/45 R18′s on my BMW 730D??
pretty close, very slightly undersized, but not too bad, 255/45 R18 would be a slight improvement, most importantly you’ll have a lot more choice and scope to save a bit of money
hi, is 7″ (width of wheel) the same as 7J
yes, the metal wheel rim width is 7 inches on a ’7J’ tyre – the letter designates the design on bead on the inside of the rim that grips the sidewall of the tyre, your tyre width ought to be slightly fatter – they ought to bulge out a bit, 225mm, 235mm etc rather than fit perfectly (215mm)
I HAVE AN 03 NISSAN 350Z THE WHEEL WIDTH IS 8 IN. CAN I PUT A 215 45 17 ON THE FRONT AND RUN 245 45 17 ON THE REAR ITS JUST FOR THE SNOW SEASON I FOUND SOME REALLY CHEAP TIRES LET ME KNOW THANKS.
AND THE CAR IS SUPPOSE TO HAVE A STAGGERED FIT THANKS AGAIN.
I have a grand cherokee 2008 with 245 60 18s and am thinking of buying 285 75 16 – will this fit? will it destroy handling?
HI I have a 2011 Santa Fe its original wheel size is 235/65 R17 can I put winter tires and rims at 215/70 R16?
Can I use 195/60/R15 tires with 15″ rim instad of 205/55/R16 installed on 16″ and what is effect on vehicle height.
I have a Citroen Berlingo XTR with 215/55/16 rims. Can I put my old Michelin Alpin 205/55/16 tyres on?
Thanks,
Brian
NO PROBLEM CHIEF
Hi there, I have a VW Touareg with stock 20inch rims and currently have hankook ventus all seasons 275/40R20 106V. I want to get new tires with more side profile eg 275/60R20 instead of 275/40R20. Would this cause any adverse affect to the handling of the car?
your tuareg it’s aready a very slow car : with those tyres you want to put on it will be embarassing for you when an honda fit 1.4 will leave you on dust.dont go more than 275 45 20 your car will piss you of.
YOU CANNOT DO THAT CAUSE OF ABS AND TRACTION CONTROL SYSTEM IF U WANT TO CHANGE THE TIRE PROFILE YOU GOT TO CHANGE THE RIM SIZE EXEMPLE YOU HAVE 275/40R20 YOU COULD PUT 245/55R18 AND HE DOESNT AFFECT YOUR ABS AND TRACTION CONTROL SYSTEM YOU COULD NOT IF U STAY WITH THE SAME RIM SORRY BODY
My SAAB is fitted with 225/55 R17 tyres. Is it safe to fit 225/45 R17 winter tyres?
AT 120 KPH YOU GONNA ROLL AT ENV 117 KPH ITS GOOD BUT NOT PERFECT
Your rolling radius calculation is incorrect and it also has incorrect units. It should be in mm, cm is too big. Somehow your speed delta comes out correctly… Maybe it is actually rolling circumference you have listed instead of rolling radius?? Just trying to help…
rolling circumference is exactly what is meant dude, just bad terminology
I have my stock tire and wheel in my Toyota VIOS: 205/45/R17 and planning to replace it with R18 or R19. Please give me some advice. Thanks!
franklin
Hi, I have a Mazda 2 1.3 active. The tyres that i have on the car now is 175/65/14 but would like to chage to 17″ rims and tyres. any sugestions?
thank you…
205/40R17 WITH 7.5 INCH WHEEL
hi i have 1996 chevy beretta can i put 245 45 16 rear wheels ?
Great post! This is important when you are buying rims for your car as well. Making sure that you have the right size can save you a lot of time and money.
hi, I have the following on my car, 225/40/18 front and 255/35/18 on rears, both runflats. Can I put 225/45/18 on front and 255/40/18 on the rears in runflats?
I SUGGEST TO U TO STAY WITH THE SAME SIZE BECAUSE YOUR RIM AS SPECIFIED WITH THIS KIND OF TIRE IF U DONT WANT PROBLEM BUY THE SAME SIZE
Hi – I’ve got 275/55/17 summer tyres on 8.5″ rims and want to change to 245/70/17 winter tyres. Speedo reading 10% low at moment, so using these ‘taller’ tyres should help? Can anyone see any problems? Will tese tyres fit on the rims?
hi ihave a peugeot 206 the tyre size at the moment is 175/60/14 i want to change them to alloys (ford alloys) size 195/60/15 does any one know if these will fit an what effects they might have thanks