Three bands, and the order they are applied in
Overtime pay is not one number multiplied by one rate. It is the same week of hours sorted into bands, each paid differently, and the sorting order decides the answer. This tool applies the day first and the week second, which is the order the rules themselves are written in.
Per day: double time = hours over the daily double-time line · overtime = what is left over the daily line · regular = the rest. Then across the week: regular hours beyond the weekly line become overtime.
The daily threshold is the number of hours after which a single day earns a premium — eight in California and in federally regulated Canadian workplaces, and nothing at all under the US federal standard, which only counts the week. The daily double-time line sits above it where one exists. The weekly threshold is the familiar forty. The multiplier is what the premium hours are paid at, usually one and a half.
An hour is paid once, at its highest band
This is the rule most spreadsheets get wrong, and it is worth stating plainly: daily and weekly thresholds do not stack. An hour that has already been uplifted because the day ran long is not uplifted again because the week ran long. It is counted once, at the highest band it qualifies for.
The consequence is easy to check and easy to get backwards. Five nine-hour days in California produce five overtime hours, not ten — one per day on the daily line, and nothing further on the weekly one, because only forty regular hours remain and forty is the weekly threshold. A calculator that adds the two separately reports ten, inflates the gross, and is wrong in a way that survives a casual look at the total.
The same week under two rule sets
Forty-five hours — nine a day, Monday to Friday — at twenty dollars an hour. Under the US federal standard there is no daily threshold, so the week is 40 regular hours and 5 overtime, and the gross is $950.
Under California’s rules the same week is sorted differently: each day crosses the eight-hour line, so the overtime is daily rather than weekly. The bands come out at 40 regular and 5 overtime — and the gross is $950, the same figure by a different route. That coincidence is instructive: the rules differ, the arithmetic differs, and for this particular shape of week the answer does not. It stops being a coincidence as soon as the days are uneven.
Move the hours around — a fourteen-hour Monday and four eight-hour days, forty-six hours in all — and California produces 2 hours of double time above the twelve-hour line, 4 of overtime below it, 40 regular, and a gross of $1,000. Same hours, different distribution, different pay.
All three figures are produced by the same engine as the calculator above, at the time this page is built.
When the defaults do not fit you
Only 3 jurisdictions carry published thresholds here, and there are far more than that in the world. Rather than guess at the rest, the tool lets you enter your own — a weekly line, a daily line, a multiplier, a double-time line — and then says on the result that the thresholds are yours and not a published rule. That is a deliberate trade: a calculator that quietly applies American thresholds to a Polish contract gives a confident wrong answer, which is the worst kind.
The published entries are statutory minima, retrieved 2026-09-24. A contract or a collective agreement can be more generous and many are — double time on Sundays, a premium after ten hours rather than twelve, a shorter week. Where yours differs, the custom fields are the right place to put it.
What this does not settle
This is arithmetic on hours and thresholds, not an employment-law opinion. It does not know whether you are exempt from overtime at all — a question that turns on duties and salary level, not on hours — and an exempt employee’s week produces a number here that means nothing for their pay. It does not model the regular rate of pay as the FLSA defines it, which can include non-discretionary bonuses and shift differentials and is often higher than the base hourly figure people type in.
It does not handle a workweek that starts on a day other than Monday, alternative workweek schedules, seventh- consecutive-day premiums, on-call or travel time, or tax and deductions of any kind — the gross here is gross. And where a figure carries a legal or contractual consequence, confirm it against your agreement and the authority that publishes the rule before relying on it.
Sources
Thresholds and multipliers: the authorities below, each stated with the jurisdiction it governs and the date the figures were retrieved. The generic option carries no authority and says so on the page.