Hours Calculator
Work out the time between two times, total your work hours with lunch breaks and overtime, or fill in a full weekly time card. Supports 12-hour and 24-hour (military) time, decimal-hour output, overnight shifts, and an optional pay rate — worldwide.
Choose a quick "time between two times" calculation, or switch to the weekly time card to total a full work week with breaks and overtime. Turn on a pay rate to see your earnings too.
* Overtime rules vary by country, state, and employer — the options here (over 40 hrs/week or 8 hrs/day at 1.5×) are common conventions, not legal advice. Pay estimates are gross (before tax and deductions). Always confirm against your employer's policy and local labor law.
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What Is an Hours Calculator?
An hours calculator is a free online tool that works out how much time falls between two times — and adds up your total work hours across a day or a full week. It handles the fiddly parts automatically: converting between hours and minutes, deducting lunch breaks, dealing with shifts that run past midnight, and turning the result into decimal hours for payroll. No more counting on your fingers or wrestling with a 60-minute (not 100) clock.
Our hours calculator does two jobs. The quick mode finds the time between two times with an optional break. The weekly time card mode totals clock-in/clock-out times for every day of the week, applies overtime rules, and — if you enter a pay rate — shows your estimated gross earnings.
How to Use This Hours Calculator
- Pick a mode — quick "time between two times," or the full weekly time card.
- Enter your times — use the time picker (it accepts 12-hour or 24-hour input depending on your device).
- Add breaks — enter lunch or break minutes to deduct them from the total.
- Optional: add a pay rate — and choose an overtime rule to estimate gross pay.
- Read your result — in hours and minutes, decimal hours, or both.
How to Calculate Hours Between Two Times
The trick is that time isn't decimal — there are 60 minutes in an hour, not 100. To subtract two times by hand, convert both to minutes since midnight, subtract, then convert back:
Hours = Total minutes ÷ 60 (whole part)
Minutes = remainder
Decimal hours = Total minutes ÷ 60
Example: 9:00 AM to 5:30 PM. That's (17×60 + 30) − (9×60 + 0) = 1050 − 540 = 510 minutes = 8 hours 30 minutes = 8.5 decimal hours. Subtract a 30-minute lunch and you're left with 8 hours flat.
Hours and Minutes vs Decimal Hours
Payroll systems usually want decimal hours, not "8 hours 30 minutes." The conversion divides the minutes by 60:
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 min | 0.08 | 35 min | 0.58 |
| 10 min | 0.17 | 40 min | 0.67 |
| 15 min | 0.25 | 45 min | 0.75 |
| 20 min | 0.33 | 50 min | 0.83 |
| 30 min | 0.50 | 60 min | 1.00 |
So 8 hours 15 minutes = 8.25 hours, and 8 hours 45 minutes = 8.75 hours. Our calculator shows both formats automatically.
Overnight Shifts and Times Past Midnight
If your shift starts at 10:00 PM and ends at 6:00 AM, a naïve subtraction gives a negative number. The fix is to recognise the end time falls on the next day and add 24 hours. Our calculator's overnight option does this automatically — 10:00 PM to 6:00 AM correctly returns 8 hours.
How Overtime Is Calculated
In the United States, the Fair Labor Standards Act sets overtime at 1.5× the regular rate for hours over 40 in a workweek for non-exempt employees. Some states (like California) also apply daily overtime over 8 hours. Our time card mode supports both common rules:
- Weekly: hours beyond 40 in the week are paid at 1.5×.
- Daily: hours beyond 8 in a single day are paid at 1.5×.
Overtime law varies by country and state, so treat these as common conventions rather than legal advice. Once you know your gross hours and pay, see what actually lands in your account with our Paycheck Calculator.
12-Hour vs 24-Hour (Military) Time
24-hour time (military time) avoids AM/PM confusion: 1:00 PM is 13:00, 5:30 PM is 17:30, and midnight is 00:00. To convert PM times to 24-hour, add 12 to the hour (except 12 PM, which stays 12). To convert 24-hour times after noon back to 12-hour, subtract 12 and add PM. Our calculator accepts whichever your device uses, so you don't have to convert manually.
Common Uses for an Hours Calculator
- Payroll & timesheets: total weekly hours in decimal for wage calculation.
- Freelance billing: add up billable hours across a project.
- Shift planning: check shift lengths including overnight shifts.
- Study or work logs: track time spent on tasks.