# Tire Size Calculator ISO/LT — Tire size calculator

> Calculate tire and wheel fitment, stretch, and speedometer error. (iPhone/iPad app by Nikita Morozov.)

- Source: https://appshunter.io/ios/app/tire-size-calculator-isolt/id892154550 (this page in markdown: same URL + `.md`)
- Developer: [Nikita Morozov](https://appshunter.io/developer/892154553)
- Category: Utilities, Reference
- Price: Free with in-app purchases
- Rating: 4.20/5 from 101 App Store ratings · 72 written reviews indexed
- Age rating: 4+
- Requires: iOS 18.0 · 2 MB
- Languages: American English, Czech, French (France), German (Germany), Hebrew, Italian, Russian, European Spanish
- Released: 2014-07-06
- Data updated: 2026-09-23
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/tire-size-calculator-isolt/id892154550/reviews.md

## What is Tire Size Calculator ISO/LT?

Will the new wheels fit?

Enter the tire and wheel you run now and the ones you are considering. The app draws both to scale, one over the other, from the same hub mounting face — so you can see how much further the new rim pokes out, how much closer it sits to the strut, and how much taller the whole wheel becomes.

THE DRAWING
Both wheels are drawn in cross-section on a shared axis, with the hub mounting face as the reference line. Pinch to zoom in up to 6x: the rim opens out into a real flange-and-drop-centre profile, a ruler appears along the top, and every dimension gets its own callout — rim width, section width, offset, backspace, and the gap between the two rims inside and out.

SIXTEEN MEASUREMENTS
Old and new side by side, each row with the difference:
• Disk width, tire width, tire height
• Overall diameter and circumference
• Poke, inset, backspace
• Speed error, plus what your speedometer will read at two speeds you pick
• Ride height gain and arch gap loss
• Suspension clearance, fender clearance, scrub radius

VEHICLE CATALOG
Don't know your factory sizes? Choose a make, a year and a model, and the app lists the wheel sets the car was sold with — staggered sets included — along with its spec sheet: generation, body, engine, power, bolt pattern, PCD, stud holes, centre bore and tire pressures. Tap a set to drop it straight into the comparison.

UP TO SIX SETUPS
Line up six wheels at once and swipe between them. Every setup holds a front and a rear axle, so staggered fitments stay staggered instead of being averaged away.

BOTH NOTATIONS
ISO metric (205/55 R16) and LT high flotation (33x12.50 R15).

YOUR UNITS, YOUR LANGUAGE
Millimetres or inches, km/h or mph. English, Русский, Italiano, Deutsch, Français, Čeština, Español, עברית.

SHARE IT
One tap turns the drawing and the full comparison table into a single image — send it to a friend, a forum thread or your fitter.

WHAT IS FREE AND WHAT IS NOT
The calculator, the scale drawing, all sixteen measurements, sharing, both notations, every unit and all eight languages are free, comparing two setups side by side.

Full access is an optional monthly subscription. It adds the vehicle catalog, the rear axle as a fitment of its own, and up to six setups at once. It renews automatically until cancelled, and you can cancel any time in your Apple Account settings.

No ads, no sign-up. The maths runs on your device; only the vehicle catalog needs a connection.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://wwf.kvarum.app/privacy

## Key features

- Wheel Fitment Calculation
- Tyre Stretch Analysis
- Rolling Radius Measurement
- Speedometer Error Calculator
- Multiple Wheel Comparison
- Save Results as Image
- Truck Wheel Calculator

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Unlock app | $2.99 | one-time |


## What do users think of Tire Size Calculator ISO/LT?

Overall sentiment: positive

**Pros**

- 👍 Simple and intuitive interface
- 🚫 No ads or unnecessary content
- ✅ Useful for comparing wheel and tire setups
- 💡 Visualizes changes clearly
- 💰 Worth the cost/donation
- 🚀 Fast and easy to use
- 🤓 Helps find deals on off-size tires
- 🔧 Great for precise stance tuning
- ✨ Saves from buying wrong sizes
- 🏆 Long-term user satisfaction
- 💯 Accurate measurements
- ✅ Essential for customization

**Cons**

- 🐛 Speed calculations incorrect
- 📏 Measurements can be backwards
- 🔠 Language issues (Russian)
- 🔄 Old version preferred by some
- 🎛️ Difficulty switching units (mm to inches)
- 📏 Sidewall height missing
- 📐 Graphic display issues with large tires
- 🎛️ Limited customization options for existing setups
- 📐 Incomplete graphics
- 🎛️ Width input errors
- 🔄 New version issues
- 🎛️ Metric units only
- 📐 Visuals can be crude
- 🎛️ Not ideal for trucks/large tires
- 📐 Graphics need work
- 🎛️ Tire sizes too small in visual
- 🔄 Speedo error reversed
- 🎛️ Not all measurements visible
- 🎛️ Only one axle centerline in new version
- 🎛️ No Imperial readings

**Commonly reported bugs**

- Speedometer calculations are incorrect (reads higher when upsizing, lower when upsizing)
- New version is in Russian with no option to change language
- New version does not allow tire size changes
- Half width input does not work
- Measurements are backwards (speed error reversed)
- Tire sizes too large for visual display
- New version has incorrect axle centerline alignment

**Most requested features**

- Add clearance between tire and fender
- Allow input of different front and rear sizes
- Ability to select, zoom, and save pictures
- 360-degree view option
- Option to switch between metric and imperial units
- Include sidewall height calculation
- Show speedometer reading vs. actual speed
- Add option to enter knuckle or brake caliper clearance
- Allow saving of different setups
- Improve graphic representation of wheel size combinations
- Add speed limit comparison above 60 mph
- Allow input of half width values
- Add inches option

## Recent user reviews (10 of 72)

All indexed reviews: https://appshunter.io/ios/app/tire-size-calculator-isolt/id892154550/reviews.md

### 3/5 — Update sucks

*2026-09-17, version 4.1.1*

Since you updated it’s much harder to use, I can’t separate the wheels in the image anymore to quickly see which is bigger, and you falsely say a bigger wheel makes you go slower? No if your speedometer says 60 and you have bigger wheels it will be going faster. It’s also hard to select certain sizes as the curser only want to go to the front of number making it difficult to delete a single digit, double clicking selects the whole number and you have to type the whole number again.
There is no back button, you have to tab all the way through the numbers to get keyboard to disappear. It was so much cleaner and easier to use before.  Now I wouldn’t even fathom of paying for this. There’s lots of free tire comparison apps which are free.

### 3/5 — Good

*2026-09-10, version 4.1.0*

It’s good. Bought the app a couple of years ago because they said it was either the base app or premium with a one time purchase. Now it’s subscription and I lost access to everything I had and I’m forced to buy a subscription even though I already made the one time purchase years ago. It’s the only reason I give 3 starts, because it’s actually useful and good quality app.

### 5/5 — Выручало меня не рад

*2025-03-29, version 3.10.0*

Лучшее приложение, очень простой интерфейс и без рекламы. За это отдельный респект. Пользуюсь уже несколько лет. Спасибо.

### 5/5 — Это шедевр

*2024-12-16, version 3.9.1*

Не знаю чуваки, чего вы ждете от этого приложения. Я считаю это просто шедевр. Я кучу колес уже прогнал через это приложение. Реально наглядно понятно что да как поменяется относительно сток колес. Или текущий колес. Резину найти подобрать, вылеты. Господи. Никита который это разработал. Чел, просто спасибо тебе большое. Ты очень меня выручил много раз уже!

### 5/5 — Great app

*2024-10-26*

I wish the app can let you add the clearance between the tire and fender neigh but great app I love it

### 5/5 — Nice App

*2024-09-04, version 3.9.0*

I really like this App, no pubs no garbage just useful information. Thank you for your work!

### 5/5 — Awesome work, so handy

*2023-05-14*

Paid for the app, worth it

### 5/5 — Easily the Best Tire Size App!

*2023-02-03*

This is a fantastic app that does exactly what it says it will. I’ve been using it for many years now since it was first released and it never disappoints. 🏆

* It’s free, but you should definitely consider donating to support the developer and quality, purpose-built apps like this. 🍺

* No data-mining or tracking! 🎉

* Particularly great for finding deals on slightly off size tires that are still a perfect fit for you car without looking ridiculous. Also great for if you have a specific goal like increasing tire surface area on the road for better overall grip and that kind of thing. 🤓

### 5/5 — Great App but fix ride height gain

*2022-05-17, version 3.7.1*

Easy to measure, compare & visualize wheel fitment. Couldn’t ask for better. Only criticism is during calculations, it shares two ride height gain calculations. Im assuming one of the other is fender clearance.

### 5/5 — Spot on

*2022-05-12, version 3.7.1*

Really useful app, especially if you are mad about fine stance tuning where every mm counts when it comes to widen your track but not rubbing suspension or fender / arch.

## Frequently asked questions about Tire Size Calculator ISO/LT

### What does the Tire Size Fitment app do?

This app helps users calculate various aspects of tire and wheel fitment for vehicles. It provides tools to analyze tire stretch, rolling radius, and potential speedometer errors when changing tire sizes.

### What are the key features of this app?

Key features include calculating wheel fitment, analyzing tire stretch, determining rolling radius, and a speedometer error calculator. It also allows for comparing multiple wheels, saving results as images, and includes specific calculators for truck wheels and clearance.

### Is this app free to use?

The app is free to download and use, but it offers in-app purchases. This means some features or advanced functionalities may require an additional purchase.

### Who would benefit from using this app?

This app is ideal for car owners, mechanics, and automotive enthusiasts who are considering changing their vehicle's tires or wheels. It helps them understand the implications of different sizes on performance and accuracy.

### Can I compare different wheel and tire combinations?

Yes, the app allows for several wheels comparison, enabling users to see how different combinations might fit and perform. You can also save your results as an image for easy reference.

## Version history (last 5 releases)

### 4.1.2 — 2026-09-19

Fixed an input bug 
Improved a blueprint

### 4.1.1 — 2026-09-10

Added possibility to restore past purchases

### 4.1.0 — 2026-09-08

FULL ACCESS

A new optional subscription. Three things move behind it. Everything else stays free.

Still free, as before:
• The calculator, the scale drawing and all sixteen measurements
• Two setups compared side by side
• Sharing the comparison as a single image
• ISO metric and LT high flotation
• Millimetres or inches, km/h or mph, and all eight languages

Full access adds:
• The vehicle catalog — every factory wheel size for a make, a year and a model
• The rear axle, set separately from the front, for staggered fitments
• Up to six setups at once instead of two

Nothing you have saved is deleted. If an earlier version left you with more than two setups, every one of them is still there and still editable — the subscription is only needed to add another.

Already subscribed and setting up a new device? Restore Purchases is on the Full access screen, in the menu.

### 3.10.2 — 2026-05-11

Bug fix

### 3.10.1 — 2025-04-02

Bug fix

## Apps similar to Tire Size Calculator ISO/LT

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Tire Size Calculator - Upsize](https://appshunter.io/ios/app/tire-size-calculator-upsize/id1590813057) | 1.1 (7) | Free | Utilities |
| [Wheel Size](https://appshunter.io/ios/app/wheel-size/id1508194128) | 4.8 (60) | Free | Utilities |
| [Tire Sizes](https://appshunter.io/ios/app/tire-sizes/id6743722834) | 4.6 (58) | Free | Utilities |
| [Cartomizer](https://appshunter.io/ios/app/cartomizer/id1515523302) | 4.5 (518) | Free | Utilities |
| [Auto Lube Specs](https://appshunter.io/ios/app/auto-lube-specs/id1491691114) | 4.1 (82) | Free | Utilities |
| [Carman Wheel Simulator](https://appshunter.io/ios/app/carman-wheel-simulator/id6476076430) | 3.9 (9) | Free | Utilities |

## More apps by Nikita Morozov

- [This way](https://appshunter.io/ios/app/this-way/id909665478)

All apps by Nikita Morozov: https://appshunter.io/developer/892154553

## Related topics

[tire size fitment](https://appshunter.io/ios/topics/tire-size-fitment) · [wheel fitment](https://appshunter.io/ios/topics/wheel-fitment) · [wheel size](https://appshunter.io/ios/topics/wheel-size) · [tire size calculator](https://appshunter.io/ios/topics/tire-size-calculator) · [tire calculator](https://appshunter.io/ios/topics/tire-calculator) · [tire size](https://appshunter.io/ios/topics/tire-size) · [tire size correspondence](https://appshunter.io/ios/topics/tire-size-correspondence) · [fitment](https://appshunter.io/ios/topics/fitment) · [fitment industries](https://appshunter.io/ios/topics/fitment-industries) · [tire rack](https://appshunter.io/ios/topics/tire-rack) · [tire sizes](https://appshunter.io/ios/topics/tire-sizes)

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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 2026-09-23.*