In Excel: sum the cells normally with =SUM(B2:B20), then format the result as [h]:mm — the square brackets are what stop the total resetting at 24 hours.
On this page7
8.00 decimal hours
Need it as an auditable file?
Ships inside the linked template — formula-driven, unlocked, audit-ready.
What this does
Excel stores a time as a fraction of a day: 6:00 is 0.25, 12:00 is 0.5. Adding times is therefore ordinary arithmetic, and the whole difficulty is display. The standard h:mm format shows a clock time, so a total of 30 hours displays as 6:00 — it has silently dropped the whole day. The custom format [h]:mm tells Excel to let the hours accumulate past 24. To convert a time total into a decimal number of hours for a rate calculation, multiply by 24: =SUM(B2:B20)*24 formatted as a plain number gives 30.5, which times an hourly rate gives money. Times crossing midnight need =B2-A2+(B2<A2) so the negative half-day is corrected. Keep the inputs visible and clearly labelled and the whole thing stays auditable — anyone who opens the file later, including you, can see at a glance exactly what feeds the result and change one assumption without hunting through the formula. For “excel calculate time between dates”, the reliable version is a short checking loop, not just the first command that appears to work. Run it on a deliberately small range first, watch how the affected cells change, and only then apply the same setup to the full sheet. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. That is what makes a calculation you can defend to a CFO or an auditor useful in real work: repeatable, auditable, and not dependent on memory or luck.
A worked example
Daily hours in B2:B8 as 7:30, 8:15, 6:45, 8:00, 7:45, 4:30, 0:00. =SUM(B2:B8) with the default h:mm shows 18:45, which is wrong — the true total is 42:45. Select the cell, press Ctrl+1 ▸ Custom, enter [h]:mm, and it reads 42:45. For pay at €18.50/hour: =SUM(B2:B8)*24*18.5 formatted as currency gives €790.88. A shift from 22:00 to 06:00 is =B2-A2+(B2<A2) → 8:00, where a plain subtraction returns ####. Timesheets, shift totals and project hours all go wrong in the same two places — the 24-hour wrap and the missing ×24 — and both are one formatting decision away from correct. If there is any chance you will reuse this, drop it into a small template tab right now: a labelled input area on the left and the formula beside it, checked once against the tool above. Next time the same question comes up, the answer is a single paste away instead of a rebuild from memory.
In Google Sheets
Everything above works in Google Sheets too. Excel and Sheets share the formula syntax used here; only the surrounding menus are arranged differently. That portability is deliberate — learn it once and it follows you between the two tools and across Windows and Mac. Keep this page bookmarked for the next time the same question comes up. Better still, rebuild the example once in your own sheet — doing it yourself, with the tool above to check against, is what turns a copied formula into a technique you own. If you take one thing from this page on “excel calculate time between dates”, make it the habit rather than the keystrokes: set the problem up with labelled inputs, reference those cells, and let Excel do the recomputing. Bookmark the page for the syntax, but do the example once in a blank sheet and check it against the tool above — five minutes of hands-on practice fixes the method in memory far better than re-reading, and it surfaces the small snags while they are still harmless. After that the technique is genuinely yours: faster than searching for it again, and reliable enough to drop into work that other people depend on.
Common mistakes
- Leaving the total in h:mm, which wraps at 24 hours and quietly under-reports the week.
- Typing 7.30 instead of 7:30, which Excel stores as the number seven-point-three, not seven and a half hours.
- Multiplying a time total directly by an hourly rate without the ×24, which produces a figure about 24 times too small.
- Subtracting an end time from a start time across midnight and getting ####, the display of a negative time.
- Mixing text entries like "8 hrs" into the column, which
SUMignores without warning.
Frequently asked questions
How do I add up hours in Excel?
Use =SUM(range) as normal, then format the result cell as the custom format [h]:mm. Without the square brackets the total wraps at 24 hours.
Why does my time total reset after 24 hours?
The cell is formatted as a clock time. Press Ctrl+1 ▸ Custom and enter [h]:mm — the brackets tell Excel to keep counting past a day.
How do I convert a time total to decimal hours?
Multiply by 24 and format as a plain number: =SUM(B2:B20)*24 turns 7:30 into 7.5, which is what an hourly rate needs.
How do I calculate hours across midnight?
=B2-A2+(B2<A2). The comparison adds a whole day when the end time is earlier than the start, which is exactly the correction a night shift needs.