What this calculator does
This time to decimal calculator converts a complete time, hours, minutes and seconds together, into a single decimal-hour figure. Two hours and fifteen minutes becomes 2.25 hours, eight hours and forty-five minutes becomes 8.75 hours, and so on. It is the conversion spreadsheets, payroll systems and billing tools generally want instead of a broken-down time.
This is a broader calculation than converting minutes alone: it takes the whole time, including any hours and seconds present, and folds all three into one decimal-hour number. If only a number of minutes needs converting to a fraction of an hour, with no hours or seconds involved, the dedicated minutes to decimal calculator is the more direct tool for that narrower case.
The formula
Minutes are divided by 60 and seconds are divided by 3,600 to express each as a fraction of an hour, and both are added to the whole hours entered. The result is a single decimal number representing the total time in hours.
| Term | Meaning |
|---|---|
| Decimal hours | A time expressed as a single number of hours with a fractional part, such as 2.25, rather than as separate hours and minutes. |
| Hours, minutes, seconds | The three components of the time being converted, entered separately. |
| Fractional hour | The portion of an hour represented by the minutes and seconds, calculated as minutes ÷ 60 plus seconds ÷ 3,600. |
The inputs explained
| Field | What to enter |
|---|---|
| Hours | The whole number of hours in the time being converted. |
| Minutes | The number of minutes, added on top of the hours. |
| Seconds | The number of seconds, added on top of the hours and minutes, if the time is that precise. |
When to use it
Entering hours worked into a payroll or billing system
Many payroll and invoicing systems require hours as a decimal rather than as hours and minutes, so a shift or a session logged in the normal way needs converting before it can be entered.
Comparing two logged times directly
Decimal hours are easier to add, average or compare directly than a mixed hours-and-minutes format, particularly when totalling several separate time entries.
Converting a precise timed result
A timed activity recorded to the second, such as a lab procedure or a race split, converts cleanly to decimal hours here without losing that second-level precision.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
What is the decimal-hour equivalent of common clock times?
A set of common hours-and-minutes combinations, each converted to decimal hours.
| Minutes (hours fixed at 2) | Decimal hours | As decimal minutes |
|---|---|---|
| 0 min | 2.000 | 120.00 |
| 10 min | 2.167 | 130.00 |
| 15 min | 2.250 | 135.00 |
| 20 min | 2.333 | 140.00 |
| 30 min | 2.500 | 150.00 |
| 45 min | 2.750 | 165.00 |
Questions
How is this different from the minutes to decimal calculator?
The minutes to decimal calculator converts a standalone number of minutes, such as 15 minutes, into a decimal fraction of an hour. This calculator converts a full time made up of hours, minutes and seconds together into one combined decimal-hour figure, which is the more common need when converting an actual worked or elapsed time.
Why is 15 minutes 0.25 and not 0.15?
Decimal hours are a fraction of 60 minutes, not a fraction of 100. Fifteen minutes is a quarter of the 60 minutes in an hour, which is 0.25, not 0.15, which is a common point of confusion when converting by eye rather than by calculation.
Do I need to include seconds?
Only if the time being converted is precise to the second. Leaving seconds at zero is fine for anything recorded only in hours and minutes, such as most work shifts and appointments.
Can I convert a decimal figure back to hours and minutes?
Yes, the minutes to decimal calculator also converts in the opposite direction, decimal back to minutes, for the minutes-only case.
For converting a standalone number of minutes rather than a full time, see the minutes to decimal calculator. For the hours and minutes between two clock times, use the hours calculator.