How to Measure for Aftermarket Wheels

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When it comes to fitment, it can really make or break your build. Whether you're looking to stance it, track it, or simply throw on some wheels and tires, knowing how to properly measure your wheels is essential. Today Gels demonstrates how to measure the diameter, width, offset and backspacing for your aftermarket vehicle. Let us know your thoughts & what you would like to see next down in the comment section!

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[FitmentIndustries]

Did you find this video helpful ? Let us know in the comment section below. Also, be sure to cop some gear so you can get entered for a chance to win a set of ESR wheels:

[Djdonthate]

I feel like y'all uploaded this specifically for me because I keep checking the website trying to figure out what wheel size I will need

[futureporscheowner]

This video was extremely helpful, thanks guys!
Here are the sparknotes of the vid for the boys and girls
Hopefully it helps



Backspacing for your wheels (measurement)- 1:52

Backspacing: is defined as the distance from the hub mounting surface to the inside lip of the wheel (measured in inches). More backspacing puts the tire closer to the center of the vehicle. A related term is known as offset, which relates the hub mounting surface to the centerline of the rim. (2:17) for diagram

Compress your strut where you car would be on the ground 

Get a point of reference (ex. stick) that is long enough to measure (being above your brake rotors)

Find the distance of the front mounting hub to the back where  the 1st main point of contact of where anything is (ex. strut) - distance between front mounting hub  to strut (ex. 8 ⅝ inches)

BACKSPACING = 8 ⅝ inches

FrontSpacing for your wheels (measurement) - 3:55

Once you figure out back and front spacing, you will know what width you will have to work with 

FrontSpacing is measured from the inside of the fender to the front of the mounting hub.

Get a point of reference (ex. stick) that is long enough to measure (being long enough to go down from your inside fender to the same length as your mounting hub) 

Find the distance between front of the mounting hub to the inside of the fender (ex. 2 ½ inches)




Width (Measurement) - 4:55

(Backspacing + Frontspacing) - 1 inch = Maximum wheel width 

You round to the nearest inch

8 ⅝ + 2 ½  = 11 ⅛ th inches 

11 ⅛ - 1  = 10 ⅛ inches (before rounding)

Final Answer: 10 inches Width (maximum)






Diameter - 5:58

Use your best judgement for that.

Ex. Don’t run a 22 inch wheel on a BRZ or FRS




Offset - 6:23

Offset: Offset is the measured distance between the hub mounting surface and the centre line of the rim (in millimeters)

(6:39) offset diagram and explanation

Positive Offset: the mounting surface is going to move towards the outside of the car (wheel hub is pushed out towards the fenders). AKA means that the wheel is going to sink in more towards the car.

Zero Offset: mounting surface is right in the middle

Negative Offset: the mounting surface is being pushed towards the the back of the wheel towards the inside of the car while pushing the wheel out.

You need to figure out the front spacing to find the backspacing of the wheel

Once you find the backspacing of the wheel itself and the width, you can determine your offset 

Wheel backspacing = Width - Front Spacing 

Ex. (9:34) - Want to get more of a flush set up w/ a thicker tire

Width: We decide to pick a 9.½ inch wheel width (241.3mm)

Frontspacing: 2 ½ inches

Wheel backspacing = 9.5 - 2.5 

Wheel backspacing =  7 inches

Results from calculator = 44-45 mm of positive offset 

Round to the nearest offset mm

[thatcanadiandude]

Man!!! you have no clue how much this actually helps!! Thank you guys so much. keep the awesome vids coming!!👊👊👊

[noles]

extremely new to this, i just bought a 97 ls 400 this past friday and i gotta say if learned more in this video than probably ten previous videos from other channels

[elginplays]

Ok. Seriously thank you for this. I spent 4 hours looking how to measure wheels perfectly. And I still didn’t know

[ninjankidmaryjane]

THIS FINALLY ANSWERED ALOT OF MY QUESTIONS THANK YOU FITMENT

[NitroStreet]

I have been trying to figure out a way to calculate the perfect offset for my car.
Thank you Gels and Fitment Industries for the valuable information.

[LegendaryGarageYT]

Can’t lie I was always scared to get wheels with all the math involved started following you guys now it’s no big deal plus the gallery really is a lifesaver to know what you’ll see on your car

[wanglee]

This is perfect for first timers trying to learn about wheels and fitment! I've watched about 20 other videos and everyone just talks like everyone was a professional wheel installer. All they had to do was show us step by step examples as this guy did and what they rambled on would make since. Thank to this guy!

[lonelydriver]

When you started drawing on the board i got lost, like on a physics class lol. But you did explained it well, can't get any simpler than that!

[alexmonterroso]

This is the most helpful video that I’ve seen so far
Thanks so much for posting this

[sneakwastaken]

Offset explanation is really good, thank you. I finally get it. Also great guide on measurements.

[LeavEyeDDrum]

You guys do a great job. Keep up the great content! I love this channel!

[cakesandcarsco.]

Videos saved; Will be watching this video a few times to make sure I fully understand; wouldn’t want to pay any restocking fees 😅

[adanarceo]

Thanks a lot my brother, this wheel off set explanation is clear as the water.
I’m planning to get some wheels and this is very helpful!
Thanks again!👍🏽

[ZeroNino]

Hells Yeah!! This helps a lot! Useful information I was looking for. Thanks guys.... Keep up the good work 👍

[SoundBankzRec]

Reminds me of my math teacher 👨‍🏫 still don’t get it 😴🤣

[suko_gg]

Thank god for this video 😭finally after months of trying to figure out what my future wheel fitment was going to be I did it thanks to you guys

[Tito]

Thanks for the video. This information is very important to know which rin to buy correctly!