ISO week calculator

Determine ISO week and week range.

Result

Logic

ISO week calculator

Datum, Dauer und Timestamp werden mit Browser-Date-APIs lokal berechnet.

Example

Input

2026-05-18 to 2026-06-01

Result

14 days

Common mistakes

Copying results without context
Ignoring rounding
Using output without a plausibility check

Runs locally in the browser

Inputs stay in your browser. Toolwise does not store calculations.

Check

When is the result reliable?

How does ISO week calculator calculate?

ISO week calculator uses this visible logic: Datum, Dauer und Timestamp werden mit Browser-Date-APIs lokal berechnet. Example values and common mistakes are shown next to the tool.

Do inputs stay local?

Yes. The calculation runs in the browser. Toolwise does not send inputs to a server or load external calculation modules.

What should I do next?

Copy the result or pass it locally to Timestamp converter if you want to continue the workflow.