Contact
Need a hand with a comparison?
Find a guide for the task you are working on, or email TireSpan with a reproducible example.
How can we help?
Learn to enter tire sizes, compare wheels, save and restore projects, import JSON and download CSV, SVG or PDF reports.
The method behind the numbers
Review TireSpan’s tire geometry, circumference and speed formulas, wheel offset signs, unit conversions, rounding and source limits.
Save and restore a comparison
Save a named project in your browser, reopen it, undo deletion or restore a JSON backup. Understand temporary mode and storage failures.
Find a quick answer
For a rejected size, read the input guide. For a missing saved project, read the local-storage and restore guide. For a download problem, read the export guide and keep the current comparison open while trying again.
Keep useful details for a report
A useful issue report identifies the page, the action, the two public size markings or wheel dimensions, the message shown and the browser version. Avoid sharing a personal project file when a simple example reproduces the problem. Do not include account passwords or payment information.
Email TireSpan
TireSpan is the public operating name for this website. For support, privacy questions or accessibility feedback, email support@tirespan.site.
This page does not submit a form. Sending an email uses your email service and shares the message and sender details you choose to send. Please leave personal project files out of your first message when a simple example will do.
Questions about a particular vehicle
TireSpan cannot inspect a vehicle or approve a replacement. For vehicle-specific fitment, rating or clearance questions, consult the relevant manufacturer information and a qualified tire or wheel professional.