Our calculation principles

Every calculator on Worktimeatlas is built around a defined mathematical task. We prefer simple, inspectable formulas over opaque scores. The calculator page explains what each input means and describes assumptions that could change the output.

Time and overnight calculations

For clock-time tools, a shift end that is earlier than the start may be treated as occurring on the following day. Break deductions are only applied when the user enters them or when the calculator clearly displays a default that can be changed.

Decimal hours

Decimal-hour conversions use 60 minutes per hour. For example, 15 minutes is 0.25 hour, 30 minutes is 0.50 hour and 45 minutes is 0.75 hour. We avoid presenting clock-style values such as 7:30 as though they were the same as 7.30 decimal hours.

Weekday and schedule assumptions

Workday tools count Monday through Friday unless the page states otherwise. Public holidays are not automatically removed because holiday calendars vary by location and organization. Schedule previews such as 4/10, 9/80, Panama or DuPont are examples of common patterns; an employer may use a different start date, rotation or variation.

Testing and revisions

Before publication, calculator modes are tested with simple examples that can be checked manually. Content and interfaces may be updated when we find a clearer explanation, a bug or a usability issue. If you report an error, include enough detail for us to reproduce it.