Tire Size & Fitment Upsize

Not claimed

Before you spend several hundred on new tires, find out what they will actually change

Why we expect it: A clear, practical utility that solves a real expensive decision, with a thoughtful description and a fair free tier that works offline.

Get it on theApp Store

Visit site Add rating

In short

Tire Size & Fitment Upsize compares two tire sizes and shows the real diameter change, ride height shift, gearing effect, and speedometer error. It is aimed at drivers of cars, light trucks and motorcycles weighing a tire swap. One standout point: all calculations run on the device, so no signal is needed.

Summary by Debuts, based on the App Store listing.

About

Before you spend several hundred on new tires, find out what they will actually change.

Tire Size compares any two sizes and tells you the truth about the swap: the real diameter difference, how much the ride height moves, what happens to your gearing, and how far out your speedometer will read.

WHAT IT TELLS YOU

Speedometer error, in figures. Your speedometer is calibrated for the size that left the factory. Change the rolling diameter and it lies to you. This shows by how much, at 60 mph for free, and at every speed you drive with Pro.

The diameter and sidewall change. In millimeters and in inches, with the percentage difference, so you know whether it clears.

Ride height and clearance. How much higher or lower the car sits, and how much closer the tire gets to the arch.

Effective gearing. A taller tire changes your final drive ratio whether you wanted it to or not. See it before you feel it.

Both notations. Metric like 225/45R17 and imperial like 33x12.50R15, in the same comparison. Cars, light trucks and motorcycles.

Sizes that fit. Going up a rim size? It lists the sizes that stay within 3% of the one on the car.

Saved vehicles (Pro). Keep your stock, winter and upgrade sizes for each car and switch with one tap.

Share the comparison with your shop, or with whoever is telling you it will be fine.

WHAT IS FREE

People rate it

No ratings yet. Tried it? Be the first to rate it.

More Utilities apps

Best new Utilities apps this week

Discovery signals

How AI and people discover Tire Size & Fitment Upsize on Debuts

AI-readyPartly

78% described for AI to match

Discoverable nowLiveStructured data on this page and the Debuts API