# Calculators

> Free stay-day calculators that run in your browser: the Schengen 90/180 count, the date you must leave, and the day you could return. No account, nothing sent anywhere.

Source: https://doastretch.com/tools/

Free · No account · Runs in your browser

Stay-day arithmetic you can check, running the same code the Stretch app counts with.

| Tool | What it answers |
| --- | --- |
| [Schengen 90/180 calculator](https://doastretch.com/tools/schengen-90-180-calculator/) | Days used and left across the whole Schengen area, and the date you must actually be out — walking the window forward rather than subtracting, which is where a remaining-balance sum goes wrong. |

Everything here runs entirely in your browser. Nothing you type is sent anywhere, there is no account, and the arithmetic is the same module the app uses — checked against a [shared conformance corpus](https://doastretch.com/visa/) rather than written twice.

Looking for the rules themselves rather than the count? [The rulebook covers them passport by passport](https://doastretch.com/visa/).