Most people answer this with 40 and move on. The US federal government does not, and the reason is worth knowing before you use the number for anything: three different federal sources give three different answers, and one of them says there is no answer at all.
How many hours is full time? There is no single legal figure in the United States. The Fair Labor Standards Act does not define it, the IRS uses 30 hours a week or 130 a month for the employer health coverage rules, and the Bureau of Labor Statistics counts 35 or more for statistics. The familiar 40 is a convention.
That is four numbers for one question, so the useful move is to work out which one is being asked about, then carry it through to a month and a year.
Why is there no single answer to how many hours is full time?
Because the phrase is doing three unrelated jobs. It can mean the threshold your employer uses to decide who gets benefits, the threshold a tax authority uses to decide who an employer must offer coverage to, or the cut a statistics agency uses to sort a survey response into a column. Those three bodies have no reason to agree, and they do not.
The US Department of Labor is explicit about the first one. Its page on the subject states that the Fair Labor Standards Act “does not define full-time employment or part-time employment”, and that whether an employee is considered full time or part time does not change how the Act applies. The companion page on part-time employment says the Act “does not address part-time employment” at all. So in US federal labor law the category exists only because employers create it, and it carries no statutory hours figure.
That is not a loophole. It is the design. The FLSA regulates minimum wage, overtime and recordkeeping per hour worked, so the label attached to the job is irrelevant to it.
What are the three US federal answers?
Thirty hours a week, or 130 a month, for the IRS. For the employer shared responsibility provisions, the IRS defines a full-time employee as, for a calendar month, an employee employed on average at least 30 hours of service per week, or 130 hours of service per month. The 130 is not a separate rule, it is the same rule converted: 30 hours a week times 52 weeks is 1,560 hours a year, and 1,560 divided by 12 is 130 hours a month. The IRS also counts an hour of service as any hour paid or payable, including vacation, holiday, illness, jury duty, military duty or leave, so paid time off counts toward the threshold rather than against it.
Thirty-five hours a week for the Bureau of Labor Statistics. In the Current Population Survey, full-time workers are those who usually work 35 or more hours a week and part-time workers are those who usually work fewer than 35. The BLS states plainly that these definitions “are for statistical purposes only. They are not legal definitions.” The classification also follows a person’s usual schedule rather than one particular week, which is why someone who worked 30 hours last week can still be counted as full time.
No answer at all from the FLSA, as above.
How many hours is part time?
By subtraction, and it depends which of the three you started from. Under the BLS convention, part time is fewer than 35 hours a week. Under the IRS rule, an employee averaging under 30 hours a week and under 130 a month is not a full-time employee for that month. Under the FLSA, the question does not arise.
In the United Kingdom the position is similar but stated differently. GOV.UK says a part-time worker is someone who works fewer hours than a full-time worker, that there is no specific number of hours that makes someone full or part time, and that a full-time worker will usually work 35 hours or more a week. So the UK, like the US, has a convention rather than a threshold, and the convention happens to land on the same 35 that the BLS uses for statistics.
What does each threshold look like over a month and a year?
This is where the choice of number starts to matter, because a difference of five hours a week is not five hours. Every cell below is computed the same way: weekly hours times 52 for the year, that annual figure divided by 12 for the month, and weekly hours times 47 for a year after roughly three weeks of vacation and two weeks of public holidays. The 47-week column is the one that describes a year you will actually work.
| Hours a week | Hours a year (52 weeks) | Hours a month (year / 12) | Hours a year (47 working weeks) |
|---|---|---|---|
| 20 | 1,040 | 86.7 | 940 |
| 24 | 1,248 | 104 | 1,128 |
| 30 | 1,560 | 130 | 1,410 |
| 32 | 1,664 | 138.7 | 1,504 |
| 35 | 1,820 | 151.7 | 1,645 |
| 37.5 | 1,950 | 162.5 | 1,762.5 |
| 40 | 2,080 | 173.3 | 1,880 |
Two figures are worth taking from the table. The IRS threshold of 130 hours a month is exactly the 30-hour row, which is the arithmetic check that the two halves of that rule are the same rule. And the gap between the lowest common full-time convention and the highest, 30 hours against 40, is 520 hours a year at 52 weeks, or 470 across a real 47-week year. At 40 hours a week that is 520 divided by 40, which is 13 weeks, and 470 divided by 40, which is 11.75 weeks. Either way, about a quarter of a working year sits inside the word “full time”.
If you want to run your own start and finish times rather than a round weekly number, the hours calculator does the daily arithmetic, and how to calculate work hours sets out the method underneath it.
Where does 40 hours come from, then?
From a different rule that people reasonably confuse with this one. The FLSA’s overtime provision is triggered at 40 hours in a workweek for covered, non-exempt employees in the United States, so 40 became the practical ceiling of an ordinary week and then, by habit, the definition of a whole one. The threshold and the definition are separate things: crossing 40 changes what an hour must be paid at, and it says nothing about whether the job is called full time. Overtime basics covers the rule itself, including the fact that the UK has no statutory overtime premium at all.
The 2,080 in the table above comes from the same habit: 52 weeks times 40 hours. It is slightly wrong as a count of a calendar year, and working hours in a year works through why the US federal government uses 2,087 instead. The calendar side of the same question, how many working days there are in a year, has its own count.
Which number should you actually use?
Use 30 hours a week or 130 a month when the question is about US employer health coverage obligations, because that one is written into the rule. Use 35 when you are comparing yourself against BLS statistics, and remember the agency’s own caveat that it is a statistical cut and not a law. Use your employer’s or your contract’s figure when the question is about your benefits, because that is the only number with any force over your situation. And check your own jurisdiction before assuming any of them travels: these are US federal rules, and the UK example above already answers the question differently.
For anything outside those three, 40 is a convention that other people will recognize, which makes it a reasonable default and a poor measurement.
The measurement is the part nobody can look up for you. Whether your own week is 35 hours or 44 is a fact about your weeks, and most people find out by reconstructing it on a Friday, which is the least reliable moment to ask. Timeness is built for the other method: make an activity, tap once to start it and once to switch, and the week and month charts add the hours up as they happen. The app records time and nothing else, so any rate arithmetic stays in the billable hours calculator and anything to do with pay stays wherever it already happens.
Then put your own weekly figure into the table above rather than a round one. A year at 37 hours is 1,924 at 52 weeks and 1,739 across 47, and neither of those numbers is 2,080.