A time card is just arithmetic — but it is arithmetic where a small error in one
day's hours becomes a wrong paycheck. Enter your clock-in, clock-out, and unpaid
break for each day; the calculator sums your weekly hours, applies the standard
40-hour overtime rule, and shows gross pay at whatever rate you enter. Every formula
is shown, nothing is hidden.
Read this first
This calculator does the arithmetic exactly — but it is only as accurate as your
inputs. The 40-hour overtime threshold reflects the federal FLSA rule for nonexempt
hourly employees; some states (notably California) have daily overtime rules this
tool does not apply. The hourly rate field is optional and produces a gross-pay
estimate only — it does not account for taxes, withholding, or deductions. For payroll
purposes, verify results with your employer's official timekeeping system.
Enter clock-in and clock-out for each day worked, plus any unpaid break minutes. Leave a day blank to skip it. Results update as you type.
Clock-in / clock-out grid
Day
Clock in
Clock out
Break (min)
Hours
Pay settings
$
Leave blank or set to 0 to see hours only, without a pay estimate.
This week: ( decimal hours)
Total hours this week
Overtime hours
Regular hours
Gross pay (est.)
The formulas, in full
Nothing here is a black box. These are the exact calculations the tool runs — the same
arithmetic you could do with pencil and a conversion table. The only judgment calls
are the inputs you supply.
Payroll systems use decimal hours because you can multiply them directly by a dollar
rate. The table below converts common minute intervals to their decimal equivalents —
the conversion your calculator applies to every row.
Minutes past the hour
Decimal fraction
Example: 8 hrs + X mins
Why it matters
:00
0.00
8.00 h
Exactly on the hour — no conversion needed.
:15
0.25
8.25 h
Quarter-hour increments are common in timekeeping systems.
:30
0.50
8.50 h
A 30-min unpaid lunch produces a 0.5 h reduction per day.
:45
0.75
8.75 h
Three-quarter hour — the last common interval before the next whole hour.
:06
0.10
8.10 h
One tenth-hour: some employers round to 6-minute (0.1 h) increments.
:12
0.20
8.20 h
Two tenths: 12 minutes past = 0.2 decimal hours.
:18
0.30
8.30 h
Three tenths.
:24
0.40
8.40 h
Four tenths.
:36
0.60
8.60 h
Six tenths: past the half-hour.
:48
0.80
8.80 h
Eight tenths: close to the next full hour.
Formula for any value: minutes ÷ 60 = decimal fraction. For example, 37 minutes ÷ 60 = 0.6167 decimal hours. This calculator carries full floating-point precision through intermediate math and rounds only for display.
Why the 40-hour rule is a convention, not a guarantee
The federal overtime threshold is the most common rule in the US, but it is not
the only one — and it applies unevenly depending on classification, industry, and state.
The FLSA sets a floor, not a ceiling
The Fair Labor Standards Act requires nonexempt employees to receive at least 1.5× their regular rate for hours beyond 40 in a workweek. Employers can pay overtime on a more generous schedule — daily overtime, lower thresholds — but not a stingier one for covered workers. The 40-hour rule this calculator uses is the federal minimum floor for the standard case.
Exempt employees are a different category
Salaried workers who meet the FLSA's duties and salary-level tests for executive, administrative, or professional roles are generally exempt from overtime requirements. Their pay does not increase with extra hours under federal law. Whether a particular worker is truly exempt is a legal question, not one a time card calculator can answer — if you are unsure of your classification, the U.S. Department of Labor's Wage and Hour Division publishes guidance.
Some states add daily overtime on top of the weekly rule
California is the most prominent example: state law requires 1.5× for hours past 8 in a single workday and double time for hours past 12. Colorado and Alaska have similar daily provisions. This calculator applies only the federal weekly rule — for accurate results in states with daily overtime, you will need to calculate each day's premium separately and add it to the weekly total.
How to get an accurate number from this calculator
Four inputs drive the result. The two most common errors are entering break time
incorrectly and misreading the workweek start date.
Enter only unpaid break minutes
The break field reduces your counted hours. A paid break (common for short breaks under 20 minutes) should not go here — leave it at zero so those minutes count toward your total. Only enter minutes for bona fide unpaid meal periods during which you are fully relieved of duties.
Match your employer's workweek definition
The FLSA's 40-hour threshold applies per workweek, which your employer defines as a fixed recurring 7-day period. It need not run Monday–Sunday. If your workweek starts on Sunday, shift your entries accordingly — hours from different workweeks can't be combined to generate overtime, and hours from one workweek can't be moved to another to avoid it.
Use 24-hour (HH:MM) input for overnight shifts
The time inputs accept standard 24-hour format — enter 10:00 PM as 22:00. When clock-out is earlier in the day than clock-in, the calculator automatically adds 1,440 minutes to handle the overnight crossing. A shift longer than 24 hours is outside this model; split it across two rows.
Treat the pay figure as gross, not net
The calculator multiplies hours by your hourly rate to produce gross earnings — the number before federal and state income tax withholding, Social Security, Medicare, and any voluntary deductions. Your take-home pay will be lower. For an estimate of net pay, you would need your withholding elections, filing status, and applicable state rate — information payroll software handles, not this calculator.
Where to buy
Got your numbers? Here's where to pick up what you need:
The words that appear on a pay stub, a time sheet, or an HR policy — in plain English.
Workweek
A fixed, regularly recurring period of 168 hours — seven consecutive 24-hour periods. Employers set the start day; it need not be Monday. The 40-hour overtime threshold resets at the start of each new workweek. Hours cannot be averaged across two workweeks to avoid overtime.
Decimal hours
A way of expressing time where minutes are written as a fraction of an hour (minutes ÷ 60). Useful for pay math because you multiply directly: 7.5 hours × $20/hr = $150. To convert back: take the decimal portion and multiply by 60 to get minutes (0.5 × 60 = 30 min, so 7.5 h = 7:30).
Regular hours
Hours worked up to the overtime threshold — 40 hours under the federal FLSA rule. These are paid at the employee's straight-time rate. In this calculator, regular hours = min(weeklyHours, 40) when the overtime toggle is on.
Overtime hours
Hours worked beyond the threshold. Under federal law, nonexempt employees must receive at least 1.5× their regular rate for every overtime hour. Some states have lower thresholds or daily overtime rules on top of the weekly one.
Gross pay
Total earnings before any deductions — taxes, insurance, retirement contributions, and so on. It is what hours × rate produces. Net pay (take-home) is gross pay minus all withholding and deductions, and requires payroll-specific information this calculator does not collect.
Fair Labor Standards Act (FLSA)
The federal US law that establishes minimum wage, overtime pay, recordkeeping, and youth employment standards. Administered by the Department of Labor's Wage and Hour Division. Sets the federal overtime threshold at 40 hours per workweek for covered, nonexempt employees.
Exempt vs nonexempt
Nonexempt employees are entitled to FLSA minimum wage and overtime protections. Exempt employees — those who meet specific duties tests and a salary-level threshold for executive, administrative, professional, or certain other roles — are not covered by overtime requirements. Classification depends on job duties and pay structure, not just job title.
Unpaid break / meal period
A break during which an employee is completely relieved of duties and free to use the time as their own. Under the FLSA, bona fide meal periods (typically 30+ minutes) may be unpaid and excluded from hours worked. Short breaks of 20 minutes or less are generally compensable — they count as hours worked and should not be entered in the break field.
Frequently asked
Subtract clock-in time from clock-out time to get elapsed minutes, subtract unpaid break minutes, then divide by 60 for decimal hours. For example: in at 9:00 AM, out at 5:00 PM, 30-minute unpaid lunch — (17:00 − 9:00) = 480 minutes, minus 30 = 450 minutes, ÷ 60 = 7.5 hours. Sum each day across the week for the weekly total. See the formulas section above for the complete arithmetic.
Under the FLSA, nonexempt employees must receive at least 1.5× their regular rate for hours beyond 40 in a single workweek. Some states (notably California) add daily overtime rules — 1.5× past 8 hours in a single day. This calculator applies the federal weekly rule only. For state-specific rules, check the DOL overtime resources or a qualified employment attorney.
Both express the same duration. H:MM is clock-style: 7 hours and 30 minutes written as 7:30. Decimal hours express minutes as a fraction: 30 ÷ 60 = 0.5, so 7:30 becomes 7.5. Payroll uses decimal hours because you can multiply directly — 7.5 × $20 = $150. To convert any decimal back to H:MM: multiply the decimal portion by 60 to get minutes (0.75 × 60 = 45 min, so 8.75 h = 8:45). The conversion table above covers the most common intervals.
Yes, if the break is genuinely unpaid and you are fully relieved of duties. Under the FLSA, breaks of 20 minutes or less are generally compensable (they count as hours worked). Bona fide meal periods — typically 30+ minutes with no duties — may be unpaid and excluded. If your employer pays your lunch break, do not enter it in the break field; leave it at zero so those minutes count toward your total and toward any overtime threshold.
When clock-out is earlier in the day than clock-in, the raw subtraction is negative. The calculator detects this and adds 1,440 minutes (24 × 60) to get the correct elapsed time. For example, in at 22:00 (1,320 min), out at 06:00 (360 min): 360 − 1,320 = −960, then −960 + 1,440 = 480 minutes = 8 hours. This works for any continuous shift under 24 hours. Shifts longer than 24 hours are outside the model — split them across two day rows.
Gross pay is total earnings before any deductions — what hours × rate (plus overtime premium) produces. Net pay is gross minus federal income tax withholding, state income tax, Social Security (6.2%), Medicare (1.45%), and voluntary deductions such as health insurance or 401(k) contributions. This calculator shows gross pay only. Net pay requires your W-4 withholding elections, filing status, and state tax rate — that is a payroll-software function.
This calculator is built around hourly pay. Exempt salaried employees are generally not entitled to overtime under federal law, and their weekly pay does not vary with hours worked. The hours-tracking portion is still useful for any employee who needs a total, but the overtime and pay calculations apply to nonexempt hourly workers. If you want an effective hourly rate from a salary, divide the annual salary by 52 then by typical weekly hours — but that figure is informational, not a payroll basis.
Small rounding errors compound. A 0.01-hour error per day across a five-day week is 0.05 hours — at $20/hour that is $1 per week, or about $52 per year per employee. Consistently rounding down could understate wages in violation of the FLSA. This calculator carries full floating-point precision through all intermediate steps and rounds only when displaying a value to the user. The conversion table above helps you spot-check results against known decimal equivalents.
Common mistakes
Time-card errors concentrate in two places: converting minutes to decimal hours, and misidentifying which hours qualify for overtime.
Treating clock minutes as decimal tenths of an hour
Minutes and decimal hours are not the same scale. 8:30 is 8.5 hours, not 8.3 hours. The conversion is minutes ÷ 60 = decimal fraction: 30 ÷ 60 = 0.5, not 0.3. Using the minute digits directly as a decimal — a common mental shortcut — understates hours for any minute value that is not a multiple of 6, and overstates it for values like :12, :18, :24.
Subtracting clock times directly without converting to a common unit
9:50 AM to 6:10 PM is not 6:10 − 9:50 = −3:40, nor 17:10 − 9:50 = 7:60. The borrowing rules for base-60 time do not work like base-10 subtraction. The reliable approach is to convert both times to total minutes from midnight (or from a common reference), subtract, then convert back. This calculator handles that conversion — entering raw clock times in HH:MM format is safe.
Assuming all hours past 8 in a day are overtime
Federal overtime (FLSA) is based on hours worked beyond 40 in a workweek, not 8 in a workday. Daily overtime is only required in states with that provision (California, Colorado, Alaska, and a few others). In most of the US, working 10-hour days Monday through Thursday (40 hours) with Friday off means no overtime is owed under federal law, even though several days exceeded 8 hours.
Forgetting to deduct unpaid lunch breaks
A time card showing 8:00 AM to 5:00 PM is 9 clock hours, but if there is a 30-minute unpaid lunch break, paid hours = 8.5. Calculating pay on raw punch-in to punch-out without subtracting unpaid time overpays the employee and produces inaccurate labor records. Always record whether the break is paid or unpaid before entering the hours into a pay calculation.