Editorial policy
The explanations on this site are written to help you fill in and check a time card, not to sell anything. They are short, plain and written for the person doing the work.
Every legal rule mentioned is taken from the primary source and linked: overtime from the U.S. Department of Labor Fact Sheet #23 on the Fair Labor Standards Act, and rounding from 29 CFR 785.48 in the Electronic Code of Federal Regulations. State rules are mentioned only as examples; your employer and your state labor department have the final word.
No one pays to be mentioned, and there are no affiliate links. When a cited rule changes, the explanation and the calculator are updated together, and the worked examples are re-checked.