Decimal Hours Converter

About the Decimal Hours Converter

Turn a duration written as hours and minutes into decimal hours for payroll, invoices and spreadsheets — 7:45 is 7.75 hours — or turn decimal hours back into hours and minutes: 0.6 hours is 36 minutes. Type the time the way you have it (7:45, 7.75, 465 min, 7 h 45 min or an ISO 8601 duration such as PT7H45M) and see it as decimal hours, h:mm:ss, total minutes and total seconds at once.

Payroll rounding to the nearest 5 minutes, tenth of an hour or quarter hour shows how much a rounded figure differs from the exact one, a running total adds up the rows of a timesheet, and a table lists every minute from 1 to 60 in decimal hours. Everything is worked out in your browser; nothing you type is sent anywhere.

Common uses

• Entering hours worked into payroll or HR software that asks for decimal hours.
• Billing clients by the hour, the tenth of an hour (6-minute units) or the quarter hour.
• Adding up a timesheet written in hours and minutes.
• Converting decimal hours from a report or spreadsheet back into hours and minutes.
• Writing durations as ISO 8601 (PT7H45M) for data files and calendars.

The formulas

• Hours and minutes to decimal hours: hours + minutes ÷ 60 + seconds ÷ 3,600. 7:45 = 7 + 45/60 = 7.75; 1:30:30 = 1 + 30/60 + 30/3,600 ≈ 1.5083.
• Decimal hours to hours and minutes: the whole number is the hours; multiply the decimal part by 60 for the minutes. 7.75 h = 7 h + 0.75 × 60 = 7 h 45 min; 0.6 h = 36 min.
• Total minutes = decimal hours × 60 (7.75 × 60 = 465); total seconds = decimal hours × 3,600.

The converter keeps every duration in whole milliseconds and rounds only what it shows, so rows added up in the running total never drift. Minutes that are a multiple of 3 end exactly in two decimals (3 min = 0.05 h, 36 min = 0.6 h); all others repeat (1 min = 0.01666… h), which is why payroll figures such as 8.33 are approximations.

Payroll rounding: nearest 5 minutes, tenth or quarter hour

Many time clocks and payroll systems round recorded times. In the United States, the Department of Labor accepts rounding “to the nearest 5 minutes, or to the nearest one-tenth or quarter of an hour” only where it “will not result, over a period of time, in failure to compensate the employees properly” for all the time they worked (29 CFR 785.48(b)). Rounding to the nearest increment works like this:

• ¼ hour (15 minutes): 1–7 minutes past a quarter round down, 8–14 round up — the “7-minute rule”
• 0.1 hour (6 minutes): 1–2 minutes round down, 3–5 round up
• 5 minutes: 1–2 minutes round down, 3–4 round up

The converter only rounds to the nearest increment (an exact half rounds up), never always down. In the running total you can round each row, as a time clock rounds each punch, or only the total; the difference is shown, so you can check that rounding evens out. Rules differ between countries and employers.

The most common mistake: 7.45 is not 7:45

A decimal point is not a colon. 7.45 decimal hours is 7 hours and 27 minutes (0.45 × 60 = 27), not 7 hours 45 minutes — and 7:45 is 7.75 hours. Entering 7.45 for a shift of 7:45 underpays 18 minutes. When you type a decimal whose last two digits could be minutes, the converter says what it read and what to type instead.

ISO 8601 durations

Data files, calendars and many programs write durations in the ISO 8601 form PnDTnHnMnS: PT7H45M is 7 hours 45 minutes, PT1H30M15S is 1 hour 30 minutes 15 seconds, and P1DT2H is a day and 2 hours (counted here as 26 hours). The converter reads them and shows every result in that form too. Years and months are not accepted, because they have no fixed length in hours.

Limitations

• A day is counted as 24 hours and a week as 7 days; clock changes for daylight saving are not part of a duration. Use the Time Duration Calculator for the time between two dates and times.
• For clock-in and clock-out times, breaks and overtime, use the Timesheet Calculator; this tool converts durations you already have.
• Whether and how working time may be rounded depends on the law and the employment contract that apply to you; the rounding options only show the arithmetic.
• Durations up to 100,000 hours are accepted, to the millisecond.

Privacy

Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.