Every state follows the federal FLSA's 40-hour weekly overtime rule at minimum. A handful add their own daily-overtime, double-time, or 7th-consecutive-day rules on top of it. Pick a state below for its specific rules, a citation, and a worked example.
Paid biweekly? See the biweekly overtime calculator — overtime is calculated per workweek, not by averaging your two-week total, and that trips a lot of people up.
Most in-depth: minimum wage, tipped-wage, and exempt-salary rules
States with extra rules beyond the federal 40-hour standard: