Premium

The reference is free and stays free. Premium sells the printable sheets and the fitting worksheet: the format and the volume, never the figures.

Free forever, with no account

Every size page, the size decoder, the comparison tool, the load index table, the speed symbol table and every marking reference stay free forever, with no account and no limit.

879 size pages, each with the full decode and the geometry the code implies.
The load index table, all 151 rows, with the sources behind each one.
The speed symbol table, all 30 symbols, including the bracketed case.
The decoder and the comparison tool, with no usage limit.
Every sidewall marking reference, and every safety disclaimer on every page.

Nothing safety-relevant is ever behind a payment. A load index a fitter needs is not a premium feature.

What Premium adds

Printable reference sheets
The load index table, the speed symbol table, the load range letters and the UTQG grades, laid out and page-broken for printing and pinning up in a workshop. Every figure on them stays free to read on the page it came from.
A fitting worksheet with no line limit
Line candidate sizes up against a stock size and read the diameter, clearance and speedometer change down one column. A free worksheet holds 3 lines, which is a stock size and two candidates. Premium removes the limit.
Saved worksheets, one per vehicle
A free plan keeps 1 saved worksheet. Premium keeps as many as you name, so a workshop can hold one per vehicle instead of overwriting the last one.
Print the fitting sheet
A clean print layout of the worksheet, with the sizes, the deltas and the disclaimer, to hand to a fitter or keep with a job.
CSV export
The worksheet as a CSV, for a spreadsheet or a quote.

That is the complete list. A free worksheet holds 3 lines and 1 saved sheet, and computes exactly the same numbers a paid one does.

Everything here is free right now

No purchase is configured on this build, so every surface on the site is unlocked, including the printable sheets and the fitting worksheet. Nothing is held back and there is nothing to buy.

Open the printable sheets Open the worksheet

Access on another device

Purchases are tied to an anonymous code stored in the browser you bought from, not to an account. The Premium page shows that code while you have access; enter it on Restore to unlock another browser or device. Keep it somewhere safe - it is the only way back in.

Questions

Will the reference pages ever go behind a paywall?: No. The size pages, the published tables and the tools are the site, and they stay free. If that ever changed it would be a different site.
Do I need an account?: No. There is no sign-up, no email required and no profile. Access is tied to an anonymous code held in your browser.
How do I cancel?: From the link in your receipt email. Subscriptions renew automatically until cancelled; lifetime is a single payment with nothing to cancel.