Decimal to Time Calculator

total seconds = decimal hours × 3600, rounded to the nearest second; the panel reads that count back as whole hours, then as minutes, then as the seconds left over

decimalHours

The duration written as a plain number of hours, such as 7.75 or 0.5. Two decimal places is the granularity a payroll system reports in

total

The same duration in seconds — the exact count every other row is read from, and the row to check first if a rounded reading looks off

hoursPart

Whole hours: 7.75 hours is 7. This row keeps counting past a day instead of rolling over, so 100 hours reads as 100

minutesPart

0 to 59, the minutes left once the whole hours are taken out — 0.75 of an hour is 45 minutes

secondsPart

0 to 59. It is zero for every input with two decimal places, since 0.01 of an hour is exactly 36 seconds

totalMinutes

The same span counted in minutes: 7.75 hours is 465 minutes, and 465 × 60 = 27900 seconds agrees with the row above

Use it wherever a decimal has to go back onto a clock: a payroll export that reports 7.75 hours, an invoice billed for 2.5 hours, a spreadsheet that multiplied hours by a rate and now needs the total as h:mm, a machine or fitness log that stores time as a number. It is the exact reverse of the time to decimal calculator, so the two are worth running against each other — whatever that page turns 7 hours 45 minutes into, this one should turn back. If the number came from two clock times rather than a timesheet, that page is where the conversion starts; if you are adding two durations rather than converting one, the carry is the hours and minutes calculator's job.

1. A timesheet line of 7.75 decimal hours

   1. The whole part is 7 hours and stays as it is; only the fraction has to be converted
   2. 0.75 × 60 = 45, so the line reads 7 hours 45 minutes
   3. In seconds that is 7.75 × 3600 = 27900, which is also 465 × 60
   4. The time to decimal calculator starts from the same pair the other way round: 7 hours 45 minutes comes back as 7.75

   This is the figure a payroll system prints and the reason the conversion exists: 7.75 is what a rate is multiplied by, and 7 hours 45 minutes is what a person recognises.

2. One tenth of an hour

   1. There are no whole hours, so the answer is entirely the fraction
   2. 0.1 × 60 = 6 minutes, which is 6 × 60 = 360 seconds
   3. The whole-hours row is 0 rather than blank: the input was a real value, not an empty box
   4. A tenth of an hour is the smallest step many time clocks record, and a quarter is fifteen minutes

   Decimal hours divide the hour into hundredths of an hour, not into hundredths of a minute, which is why a tenth is six minutes rather than something like ten.

3. A hundred hours, well past a day

   1. 100 × 3600 = 360000 seconds, and 360000 ÷ 60 = 6000 minutes
   2. The whole-hours row is 100 and the minutes row is 0, because the input was a whole number of hours
   3. The sentence at the top of the panel reads 4 days 4 hours: past twenty-four hours the prose row rolls into days
   4. The two readings are both right — a timesheet line of 100 hours must stay 100, while the readable form is four days and four hours

   This is the one place the panel deliberately says the same span two ways. If you need the days and hours rather than the hours alone, read the sentence; if you need the hours a payslip expects, read the row.

The input is a duration and not a clock time: nothing here knows a date, a time zone or a day boundary, so 7.75 is always seven and three quarter hours and never a quarter to eight in the evening. Input is rounded to the nearest second, which makes the finest step about 0.0003 hours; 0.001 hours comes back as 4 seconds, and 0.99999 hours rounds up to a full hour — 1 hour 0 minutes 0 seconds out of a number that was short of one. Reading past a day is split two ways on purpose: the prose row rolls into days and the whole-hours row does not. No break is deducted, no hourly rate is applied, and no overtime rule is involved anywhere on this page.

How do I convert 0.75 hours to minutes?

Multiply the fraction by 60: 0.75 × 60 = 45, so 0.75 hours is 45 minutes. The same rule turns 0.1 hours into 6 minutes and 0.25 hours into 15 minutes. Only the part after the decimal point is converted — the 7 in 7.75 stays a 7, which is why the answer is 7 hours 45 minutes rather than 7 hours 75 minutes.

How many minutes is 7.75 hours?

465 minutes. Multiply the whole hours by 60 and add the leftover minutes: 7 × 60 + 45 = 465. The seconds row agrees, because 465 minutes is 27900 seconds and 7.75 × 3600 is the same number — the rows are one span in three units rather than three separate calculations.

Why does a tenth of an hour come out as 6 minutes?

Because an hour divides into sixty minutes and not into a hundred: 0.1 × 60 = 6. One tenth of an hour is six minutes and one quarter of an hour is fifteen, which is why a time clock that rounds to the nearest tenth or quarter of an hour is really recording six and fifteen minute steps. It also means decimal hours cannot be read by moving the decimal point two places.

What happens to a number above 24?

It is read as days in the prose row and kept as hours everywhere else. 100 decimal hours reads as 4 days 4 hours in the sentence at the top of the panel, and as 100 in the whole-hours row, because a timesheet line of a hundred hours has to stay a hundred. The minutes row continues past a day as well: 6000 minutes.

Is this the same as the time to decimal calculator?

It is the reverse of it. That page takes the parts of a time — 7 hours 45 minutes — and gives 7.75; this page takes 7.75 and gives 7 hours 45 minutes back. Running one value through both is a quick way to check a payroll figure, and the two always agree because both work from the same rounded total second count rather than from separately rounded minutes.

• SP 330, Section 4 — Units outside the SI accepted for use with the SI (Table 8: 1 h = 60 min = 3600 s) — NIST
• 29 C.F.R. § 785.48 — Use of time clocks (working time recorded to the nearest tenth or quarter of an hour) — Legal Information Institute, Cornell Law School