# Tire Size & Fitment Upsize — Speedo error, gearing, chart

> Speedo error, gearing, chart (iPhone/iPad app by Yaniv van der Stigchel.)

- Source: https://appshunter.io/ios/app/tire-size-and-fitment-upsize/id6816711228 (this page in markdown: same URL + `.md`)
- Developer: [Yaniv van der Stigchel](https://appshunter.io/developer/6791340700)
- Category: Utilities, Reference
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 5 MB
- Languages: American English, German (Germany), Brazilian Portuguese, Russian, Mexican Spanish
- Released: 2026-09-29
- Data updated: 2026-10-19

## What is Tire Size & Fitment Upsize?

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

The full comparison — diameter, height, speedometer error and gearing — is free, and stays free. A single payment adds saved vehicles, up to four sizes side by side, and the full speedometer table.

No account. No subscription. No ads. Every calculation runs on the device, so it works in a parking lot with no signal.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Tire Size Pro | $3.99 | one-time |


## Is Tire Size & Fitment Upsize safe?

Not enough ratings yet to assess Tire Size & Fitment Upsize.

## Is Tire Size & Fitment Upsize legit?

Tire Size & Fitment Upsize appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for Tire Size & Fitment Upsize is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 2 releases)

### 1.1 — 2026-10-08

Scan your tire: the size, load and speed rating and DOT date are read on your device, with a tire-age verdict.
Your first run needs just one size to get an answer.
The garage shows each tire's age, and the drawing animates the fit and the rub point.

### 1.0 — 2026-09-29

No release notes.

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## More apps by Yaniv van der Stigchel

- [Every Angle](https://appshunter.io/ios/app/every-angle/id6791340698)
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- [Gift Tracker: Christmas List](https://appshunter.io/ios/app/gift-tracker-christmas-list/id6809765243)
- [DuctWise HVAC Duct Calculator](https://appshunter.io/ios/app/ductwise-hvac-duct-calculator/id6814964642)

All apps by Yaniv van der Stigchel: https://appshunter.io/developer/6791340700

## Related topics

[tire size fitment](https://appshunter.io/ios/topics/tire-size-fitment)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-19.*