How to Calculate Hours Worked on a Time Card

The procedure in seven steps

Work through every shift the same way. Do not switch to decimals until the very end.

1. Write each punch as a clock time with AM or PM. If your card uses a 24-hour clock, keep it that way; it removes the AM/PM guesswork.
2. Subtract the in time from the out time. Work in hours and minutes. If the out minutes are smaller than the in minutes, borrow 60 minutes from the hours.
3. If the out time is earlier than the in time, the shift crossed midnight. Count to midnight, then from midnight to the out time, or add 24 hours to the out time before you subtract.
4. Take off unpaid meal breaks only. A bona fide meal period, usually 30 minutes or more with no duties, comes off. Short rest breaks stay in.
5. Check the date for daylight saving time. A night shift that runs through 2:00 AM on a changeover night is an hour shorter or longer than its clock times suggest.
6. Add the days of the workweek together in hours and minutes. Carry every 60 minutes into an hour.
7. Convert the week total to decimal hours once, at the end. Divide the minutes by 60 and round to two places. Payroll uses the decimal; the hours and minutes are your proof.

Then compare the total to 40. Under the FLSA, hours over 40 in a workweek are overtime, paid at 1.5 times the regular rate.

Worked example: one week, start to finish

Here is the week used throughout this site’s examples. It has an early start, two long days, a Saturday half-shift and one 45-minute lunch. The pay rate is $24.50 an hour.

Monday, step by step. 4:34 PM is 16:34 on a 24-hour clock. From 7:58 to 16:34: the minutes 34 are smaller than 58, so borrow an hour, which turns 16:34 into 15:94. Now 94 − 58 = 36 minutes and 15 − 7 = 8 hours, so the span is 8:36. Take off the 30-minute lunch and Monday is 8:06, or 8.10 hours.

The week. Add the six days in hours and minutes and you get 48:58. That is 2,938 minutes, and 2,938 ÷ 60 rounds to 48.97 hours. Running totals show where the 40th hour falls: 8:06 after Monday, 18:21 after Tuesday, 26:01 after Wednesday, 36:31 after Thursday. The week crosses 40 hours partway through Friday: 3:29 of Friday is straight time and the other 4:28 is overtime, and all 4:30 of Saturday is overtime.

The pay. Under the federal rule the week splits into 40:00 straight time and 8:58 overtime (8.97 hours).

• Straight time: 40 hours × $24.50 = $980.00.
• Overtime: 8:58 at $36.75 (1.5 × $24.50) = $329.53.
• Gross: $1,309.53.

Of that overtime pay, $109.84 is the half-time premium alone ($12.25 an hour for 8:58); the rest is straight time for those hours.

Each money line is figured from the exact minutes and rounded to the cent once, and the time card calculator gives the same figures.

What counts as time worked

The FLSA pays for hours worked, and the Department of Labor reads that broadly. Its Fact Sheet #22 says the workweek ordinarily includes “all time during which an employee is necessarily required to be on the employer’s premises, on duty or at a prescribed work place.” In practice:

• Work you were allowed to do counts, even if nobody asked. Staying late to finish a task or fix an error is work time. The reason does not matter.
• Waiting can count. If you are engaged to wait, such as a worker who must stay at the station for the next job, it is work time.
• On-call time on the premises counts. On call at home, free to do your own things, usually does not.
• Travel between job sites during the day counts. The ordinary commute from home to work does not.
• Early or late punches with no work do not have to be paid. Under 29 CFR 785.48(a), if you voluntarily clock in early and do no work, the employer may disregard that time. If you start working, it counts.

Training, sleep time on 24-hour shifts and overnight travel each have their own tests. Fact Sheet #22 lists them. Who decides in a dispute is your employer first, then your state labor department or the U.S. Department of Labor’s Wage and Hour Division.

Breaks: what comes off and what stays in

This is the step where most hand calculations go wrong, in both directions.

Short rest breaks are paid time. Under 29 CFR 785.18, rest periods of about 5 to 20 minutes are hours worked and must be counted. Do not subtract a 10- or 15-minute coffee break.

Bona fide meal periods are not work time. Under 29 CFR 785.19, a meal period of ordinarily 30 minutes or more, with you completely relieved from duty, does not count. If you have to eat at your desk and answer the phone, or stay at your machine, you are working, and that time counts.

Auto-deducted lunches. Some time systems take a meal break off every shift automatically. That is only right on days you actually took a full, duty-free lunch. On a day you worked through it, the deduction should be reversed. Check your stub against your own notes.

The FLSA does not require breaks at all. It only says how to count them if they are given. Some states require meal or rest breaks for adults; the break laws table covers all 50 states and DC.

On a card with a lunch, you can record the break either as minutes (out 30) or as a separate out-and-in punch pair. Monday in the example as two pairs, 7:58 AM–12:00 PM and 12:30 PM–4:34 PM, gives the same 8:06. Use one method or the other for the same break, never both.

Overnight shifts and the workweek boundary

A shift that starts at 10:00 PM and ends at 6:30 AM the next morning looks impossible on paper, because 6:30 looks smaller than 10:00. The fix is to cross midnight in two pieces: 10:00 PM to midnight is 2:00, and midnight to 6:30 AM is 6:30. Together that is 8:30; take off a 30-minute meal break and the shift is 8:00 (8.00 hours).

Which day does it belong to? For a daily total, most cards list the shift on the day it started. For overtime, the federal rule cares about the workweek, not the day. Under 29 CFR 778.105, a workweek is a fixed, regularly recurring period of 168 hours (seven 24-hour days in a row), and it can start on any day and at any hour. Once set, it stays fixed.

That matters when a shift runs across the start of a new workweek. Take a workweek that starts at midnight between Saturday and Sunday. A Saturday 10:00 PM–6:30 AM shift (no break) puts 2:00 in the week that is ending and 6:30 in the week that is starting. Each piece counts toward its own week’s 40 hours. Federal recordkeeping rules require employers to record the time and day the workweek begins, so you can ask what yours is.

Daylight saving time nights: 7 hours or 9

Clocks in most of the country move twice a year. Under 15 U.S.C. 260a, daylight saving time begins at 2:00 AM on the second Sunday of March and ends at 2:00 AM on the first Sunday of November.

• Fall back: the hour from 1:00 to 2:00 AM happens twice. A shift from 10:00 PM Saturday, October 31, 2026, to 6:30 AM Sunday, with a 30-minute meal break, is 9:00 of actual work, not 8:00.
• Spring forward: the hour from 2:00 to 3:00 AM never happens. The same shift on the night of Saturday, March 13, 2027, is 7:00 of actual work.

Hawaii and most of Arizona do not change their clocks, so there the shift is 8:00 both nights. Part of Arizona does change its clocks, so the hours and time card calculators ask whether your clock changes rather than guessing from the state. The guide to daylight saving time and night shifts covers how to write these nights on a card and how the extra hour can push a week into overtime.

Decimal hours and the most common mistakes

Converting to decimal, and why the order matters

Payroll systems multiply your rate by decimal hours. Time cards show hours and minutes. Mixing the two is the single most common error.

• Minutes are sixtieths, not hundredths. 7:40 is 7 hours and 40 minutes, which is 7.67 hours. It is not 7.40. And 7.40 hours is 7:24.
• Add in minutes, convert once. Total the week in hours and minutes (48:58), then convert (48.97). Rounding each day to two decimals and then adding can drift by a hundredth or more, because values like 20 minutes (0.333… hours) never come out even.
• Round half up to two places. 8:06 is 8.10 exactly. 7:40 is 7.666…, which rounds to 7.67. One minute is 0.02 hours.

The guide to minutes and decimal hours has the full 0–60 chart and the payroll mistakes the mix-up causes.

Mistakes priced out on the example week

Each mistake below is applied to the example week at $24.50 an hour, with the federal rule. The correct week is 48:58 and $1,309.53.

Rounding is allowed, but it has to even out. Under 29 CFR 785.48(b), employers may round punches to the nearest 5 minutes, tenth of an hour or quarter hour, provided that over time it does not fail to pay employees for all the time they actually worked. In the example week, rounding moved Friday up and two other days down. One week proves nothing either way; the question is what happens across many weeks and many workers. The guide to the 7-minute rule and time clock rounding explains the quarter-hour split and how to test a pattern.

Other mistakes that do not show up in a table:

• Averaging two weeks. Overtime is figured one workweek at a time. A 30-hour week and a 50-hour week are not two 40-hour weeks; the second one has 10 hours of overtime. Fact Sheet #23 says plainly that averaging hours over two or more weeks is not permitted.
• Assuming the workweek is Sunday to Saturday. It can start any day at any hour, so check yours before you total a week.
• Subtracting short breaks. A 15-minute rest break is paid time.
• Treating 12:00 AM as noon. 12:00 AM is midnight. Writing it wrong turns a 5-hour evening shift into a 17-hour one.

When state rules change the answer

The federal rule counts only weekly hours. Some states also count each day. From this site’s state data, the states with daily overtime rules for adults are Alaska, California, Colorado, Nevada and Oregon, and in several of them the daily rule applies only to some employers, rates or industries. California and Kentucky also have seventh-day rules.

The hours worked do not change under a state rule; what changes is how many of them are paid as overtime and at what rate. Run the example week under a rule of over 8 hours a day plus over 40 a week, with no conditions excluding you. Monday, Tuesday and Thursday each pass 8 hours, which gives 4:51 of daily overtime (0:06, 2:15 and 2:30). The remaining straight time still passes 40 on Saturday, which adds 4:07 of weekly overtime. The total is the same 8:58 here, and the gross is the same $1,309.53, but in other weeks a daily rule finds overtime the weekly rule does not. A minute that is already daily overtime is not counted a second time as weekly overtime.

For your state’s rule, its conditions and the official source, see overtime laws by state, which covers all 50 states and DC. If your pay does not match the rule as written, ask your employer first. Your state labor department or the U.S. Department of Labor’s Wage and Hour Division can investigate. This is general information, not legal advice.

What to keep, and how to check a paycheck

The employer keeps the official records. Under 29 CFR 516.2, the employer must record the hours worked each workday and the total each workweek, along with the time and day the workweek begins. Your own record is still the fastest way to catch a mistake.

1. Write down each in and out time the day it happens, plus any meal break you took or missed.
2. At the end of the workweek, total it in hours and minutes, then convert to decimal.
3. When the stub arrives, compare its regular and overtime hours to yours, in decimals, to two places.
4. If they differ, find the day. The usual causes are a missed punch, an auto-deducted lunch you worked through, rounding or a typed 7.40 that should be 7.67.
5. Bring your notes to whoever runs payroll. Most errors are fixed at this step.

Next step

Type your week into the time card calculator. It adds each day in minutes, handles overnight shifts, daylight saving nights and the workweek boundary, applies the federal rule or your state’s, and gives you a printable card and a CSV file to keep. Compare its totals with your pay stub, line by line.