Free Time Card Calculator

How the math works

Every calculation here runs in whole minutes. Your clock in and clock out are converted to minutes since midnight, the unpaid break is subtracted, and the result stays an integer until it is drawn on screen. Decimal hours and hours:minutes are two views of that same integer. A calculator that turns each day into 8.4166667 hours and adds those together disagrees with itself by a cent or two as soon as a pay rate is applied.

Shifts that cross midnight are handled explicitly: if the clock out is at or before the clock in, a day is added before subtracting, so 10:00 pm to 6:15 am is 8 hours 15 minutes, not minus 15 hours 45. That one rule is the most common defect in homemade time sheets, and why a spreadsheet built on =B2-A2 goes negative on your night shifts.

Pay follows the federal weekly rule: the first 40 hours of the workweek at your rate, and anything above 40 at one and a half times. Gross pay is worked out from the exact minute count and rounded to cents once, at the end. Rounding the hours to two decimals first and then multiplying introduces an error before the money is even calculated.

Decimal hours and hours:minutes are not the same number

7.5 hours is 7 hours 30 minutes. It is not 7 hours 50 minutes. Payroll systems work in decimal hours because you can multiply them by a pay rate; clocks work in minutes because there are 60 of them in an hour. Reading one as the other is wrong by 20 minutes every time.

Two-decimal hours are themselves a rounding: 7 hours 50 minutes is 7.8333… hours, shown as 7.83. The gap is about six seconds and every payroll system does it, but it is still a rounding — which is why the hours:minutes figure sits beside it here.

A worked week

• Monday, 9:00 am to 5:30 pm, 30-minute lunch: 8:30 elapsed, less 30, is 8:00 (8.00).
• Tuesday, 8:45 am to 5:10 pm, 45 minutes: 8:25 elapsed, less 45, is 7:40 (7.67).
• Wednesday, 10:00 am to 2:00 pm, no break: 4:00 (4.00).
• Thursday, 9:00 am to 5:30 pm, 30 minutes: 8:00 (8.00).
• Friday, 10:00 pm to 6:15 am, 30 minutes: crosses midnight, so 8:15 less 30 is 7:45 (7.75).

The week is 2,125 minutes: 35 hours 25 minutes, or 35.42 decimal hours. Nothing is over 40, so there is no overtime. At $17.35 an hour the gross is $614.48. Round to 35.42 hours first and then multiply, and you get $614.54 — six cents adrift from a single rounding, before any overtime multiplier is involved.

What the rounding rules actually say

Rounding is lawful under federal rules, within limits. 29 CFR 785.48(b) describes employers recording punches “to the nearest 5 minutes, or to the nearest one-tenth or quarter of an hour,” and accepts the practice provided it does not, over a period of time, fail to compensate employees for all the time they have actually worked. Two things follow. Rounding has to be neutral: a rule that always rounds your start up and your finish down is not rounding, it is a pay cut. And the increments the regulation names are 5, 6 and 15 minutes — ten-minute rounding is common in the wild but is not in the text.

There is a second question almost no free calculator asks: what is being rounded? A time clock rounds the punches. Most calculators round the day’s total instead, and the two disagree. Clock in at 8:53 am, out at 5:03 pm, 30-minute lunch, quarter-hour rounding: rounding the punches gives 9:00 to 5:00 less the break, so 7:30. Rounding the day’s total takes 7:40 up to 7:45. Fifteen minutes apart on one day — so this tool makes it a visible setting and always prints the exact figure beside the rounded one.

Sources: 29 CFR 785.48 (rounding), 785.18 and 785.19 (rest breaks and meal periods), 778.105 (the fixed workweek) and 778.107 (the 40-hour overtime standard), all checked against the eCFR on 8 August 2026, plus the Wage and Hour Division’s Fact Sheet #22 on hours worked. State rules can be stricter than this federal floor; find your state office through the DOL list of state labor agencies.

The edge cases, including the one this cannot fix

• Midnight and noon. 12:00 am is midnight, 12:00 pm is noon — the reverse of what many people assume, and of what some calculators do.
• Same in and out. Counted as a full 24 hours, with a warning. That is what the arithmetic says, and silently returning zero would hide a typo.
• A break longer than the shift. The day counts as zero, with a warning — never a negative number quietly dragging the week down.
• Ambiguous input is refused, not guessed. “9.5” could mean 9:05 or half past nine, so the tool asks instead of quietly costing you 25 minutes.
• Daylight saving. The tool never sees a date, so it cannot know. On the US spring-forward night a 10 pm to 6 am shift is seven actual hours; on the fall-back night it is nine. Wall-clock subtraction says eight both times. You are owed pay for hours actually worked, so on a changeover week push the clock out an hour later in the fall and an hour earlier in the spring.

What this does not model

Daily overtime, seventh-consecutive-day rules, and any state premium beyond the federal 40-hour week. Nor the FLSA regular rate: if you receive nondiscretionary bonuses, shift differentials or commissions, overtime is owed on a higher rate than your base — the overtime pay calculator handles that. No taxes, no deductions, no tips, no meal-period penalties. Also: the workweek that decides overtime is your employer’s fixed, regularly recurring 168-hour week. It need not start on Monday or match your pay period, so a biweekly paycheck is still two separate 40-hour tests. If the hourly rate itself is the question, the salary to hourly calculator works the other direction.