Time Calculator
Add or subtract hours:minutes durations and find the interval between two clock times — midnight crossover and break deductions included.
Examples
Weekly work hours
9:30 + 9:30 + 9:30 + 9:30 + 9:0047:00 (47.00 h / 2820 min) · day breakdown 1d 23h 00mFive work-day durations with full minute carrying; the total crosses a day so the breakdown row appears.
Night shift across midnight
22:00 → 06:00, break 30 min7:30 (7.50 h / 450 min), crosses midnight: yesThe end time is earlier than the start, so the interval wraps +24 h before the break is deducted.
Day with a correction
8:15 + 7:45 − 0:3015:30 (15.50 h / 930 min)Flip any row to − to subtract a fix, such as a break paid by mistake.
About this tool
Time Calculator is a purpose-built arithmetic tool for hours and minutes. Type durations in the h:mm format timesheets actually use — 8:30, 7:45, 1:50 — add or subtract as many rows as you need, and the total appears instantly in all three formats payroll work demands: h:mm with proper 60-based carrying (8:30 + 7:45 + 1:50 = 18:05), decimal hours (18.08), and total minutes (1085). No more nudging minutes across the hour boundary by hand or pasting times into a spreadsheet to get the carrying right.
The second mode answers a different question: how long is there between two clock times? Enter a start and an end time, deduct an unpaid break in minutes, and read the interval. If the end time is earlier than the start — a shift that runs 22:00 → 06:00 — the tool wraps across midnight automatically instead of returning a nonsense negative, and it says so in the result. Breaks larger than the interval produce a clearly flagged negative total rather than a silent wrong answer.
Everything about the tool is tuned for the payroll and timesheet audience. Minutes are strict: 9:75 is rejected with a hint that explains you probably meant 9:15 (nine and a quarter) or 9:45 (nine and three quarters), because decimal hours typed with a colon are the single most common time-math mistake. Totals above 24 hours also show a day breakdown, so a 32-hour week reads as 1d 8h 00m as well as 32:00. Empty rows are ignored, rows can be toggled between + and − for corrections, and your shift patterns persist in your own browser between visits.
The calculations run entirely on your device — no account, no upload, no queue. Shift schedules can be sensitive (they reveal when a workplace is staffed), and pay-related figures are personal, so nothing ever leaves the tab. If you need the opposite reformatting — turning an h:mm result like 7:45 into the decimal 7.75 that payroll software imports — the minutes to decimal converter is the companion tool for exactly that.
What this tool does not do
- Minute precision only — seconds are out of scope for timesheet and payroll arithmetic.
- The interval mode works within one wrapped day (up to 24 h); multi-day spans belong in a date calculator.
- Break minutes are rounded to whole minutes before deduction.
How to use this tool
Choose a mode
Keep “Add / subtract durations” to sum h:mm rows, or switch to “Between two times” to compute an interval.
Enter your times
Type each duration as h:mm (8:30), toggle a row between + and − for corrections, or enter a start time, end time, and break minutes.
Calculate and read the three formats
Press Calculate to get the total as h:mm, decimal hours, and total minutes — plus a day breakdown once the total passes 24 hours.
Copy or reset
Use Copy result to take the total to your timesheet, or Reset to start a fresh calculation; your input stays saved in this browser either way.
Use cases
Adding up a timesheet week
Sum daily work durations with correct carrying and read the total in the h:mm, decimal, and minutes formats your payroll process asks for.
Shift work and night shifts
Compute intervals that cross midnight — 22:00 → 06:00 — without manually adding a day, and deduct unpaid breaks in minutes.
Correcting logged hours
Toggle rows between + and − to remove disputed minutes or a duplicated entry, with negative totals flagged instead of hidden.
What each result line gives you
| Result line | Meaning |
|---|---|
| h:mm (primary) | Clock-style total with 60-based carrying, e.g. 18:05; negative totals show a minus sign |
| Decimal hours | The same total divided by 60, e.g. 18.08 — the format payroll imports expect |
| Total minutes | Raw minutes, e.g. 1085 — useful for break policies counted in minutes |
| Day breakdown | Appears above 24 h: 32:00 also reads as 1d 8h 00m |
| Crosses midnight | Interval mode only: shows whether the +24 h wrap was applied |
Every result is computed locally; break minutes are rounded to whole minutes.
Common mistakes
Mistake:Typing decimal hours with a colon, like 9:75 for nine and three quarters.
Fix:Minutes must be 00–59. Nine and three quarters is 9:45; nine and a quarter is 9:15. If you have 9.75 decimal hours, type it into the converter's decimal field instead.
Mistake:Assuming an end time earlier than the start is an error.
Fix:That is a midnight wrap: 22:00 → 06:00 is an 8-hour interval, and the tool applies +24 h automatically and labels it in the result.
Mistake:Forgetting that a break must be deducted explicitly.
Fix:Interval mode deducts the break you enter — leave it 0 only if the break is paid. A break longer than the interval yields a flagged negative total.
Frequently asked questions
How do I add 8:30 + 7:45?
Minutes add to 75, which carries into the hours: 8:30 + 7:45 = 16:15, not 15:75. The tool does this carrying for you — type both durations on separate rows, press Calculate, and read 16:15 plus its decimal form (16.25 h) and total minutes (975). Add a third row, such as 1:50, and the total updates to 18:05.
How do I calculate my work hours with a break?
Switch to “Between two times”, enter your clock-in and clock-out times, and put the unpaid break in minutes in the break field. For example, 9:00 → 17:00 with a 30-minute break gives 7:30 (7.5 decimal hours). The break is deducted before the result is shown, and the result card lists exactly how many minutes were deducted.
What happens when the end time is past midnight?
Nothing breaks — the tool wraps automatically. When the end time is earlier than the start time, it treats the interval as crossing midnight and adds 24 hours: 22:00 → 06:00 is 8:00, and with a 30-minute break it is 7:30. The result card shows “Crosses midnight: Yes” so you can see the wrap was applied.
Why is 1:60 invalid?
The colon format is base-60: minutes run from 00 to 59, so 1:60 does not exist — it is just 2:00 written wrongly. The strict check exists to catch the most common input mistake: decimal hours typed with a colon. 1.6 decimal hours is 1:36, not 1:60. If you have a decimal number, enter it in the minutes-to-decimal converter instead and it will do the split correctly.
How do I convert the result to decimal hours for payroll?
You do not have to — every total already shows decimal hours next to the h:mm value (18:05 is 18.08 h, 7:30 is 7.50 h). For a single standalone conversion, or for a full minutes-to-decimal chart with quarter-hour rounding, use the dedicated minutes to decimal converter, which goes in both directions.