Tire Size Calculator ISO/LT
Tire size calculator
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
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
Fixed an input bug
Improved a blueprint
The developer, Nikita Morozov, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Nikita Morozov
- Size
- 2.1 MB
- Category
- Utilities
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - iPad
Requires iPadOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later.
- iPhone
- Languages
English and 7 more
- English, Czech, French, German, Hebrew, Italian, Russian, Spanish
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Unlock app $2.99
- Full access $1.99
- Copyright
- © Morozov Nikita