Timesheet Calculator
Total time
15.75 hours
3 entries, kept in whole minutes so nothing is lost to rounding.
- In hours and minutes
- 15h 45m
- Amount at $115.74 an hour
- $1,822.91
How this is calculated
Time entries arrive in whatever notation you happened to use at the time, so this accepts both of the common ones. Seven thirty written as 7:30 and the same duration written as 7.5 are treated as identical, because they are. What happens next is the part that matters. Every entry is converted to a whole number of minutes and the total is summed in minutes, not in decimal hours, and only converted back at the very end. That sounds pedantic until you notice where decimal hours actually lose time, which is not in the addition but in every conversion before it. Seven minutes is 0.11666 recurring of an hour, and a timesheet that records 0.12 has already rounded before it has added anything. Forty such entries are two hundred and eighty minutes exactly, but two hundred and eighty-eight as rounded decimals: eight minutes adrift over a fortnight, in the client's favour or yours depending on which way each entry happened to round. Kept in minutes the arithmetic is exact. If a row cannot be read the whole total is withheld and the row is named, rather than that row quietly counting as zero, because an hour that silently vanishes from a timesheet becomes an hour missing from an invoice.
Worked example
Seven and a half hours is 450 minutes, six forty-five is 405, and an hour and a half is 90. That totals 945 minutes, which is 15 hours 45 minutes, or 15.75 in decimal. At $115.74 an hour that is $1,822.91. Summing 7.5, 6.75 and 1.5 as decimals happens to give the same answer here, but it does not always, and the failure is silent when it does not.
Inputs: Monday 7:30, Tuesday 6:45, Wednesday 1:30, at $115.74 an hour
Result: 15.75 hours, or 15h 45m, worth $1,822.91
What this assumes
- Durations are entered as H:MM or as decimal hours. Anything else is refused rather than guessed at.
- Minutes are the unit of record. Decimal hours are shown for convenience and rounded to two places.
- Blank rows are ignored. A row with an unreadable time stops the total rather than counting as zero.
Questions
- Can I enter 7h30m?
- No, and that is deliberate. Supporting every notation means guessing at ambiguous ones, and a timesheet is the wrong place to guess. Two formats, both unambiguous, both refused when malformed.
- Why does it show hours and minutes as well as a decimal?
- Because you record time in one and invoice it in the other. Showing both means you never have to do that conversion yourself, which is where the mistakes usually creep in.
- Does it round my time?
- Only to the nearest whole minute, and only when you enter a decimal fine enough to need it. Nothing is rounded up to the next six or fifteen minutes. If you bill in increments, round your entries yourself before you type them.