π Time to Decimal Hours Converter
HH:MM to decimal hours and back. Built for timesheets.
Converted time
How to Use the Time to Hours Converter
Pick a direction. Time-to-decimal turns hours and minutes into the single decimal number your timesheet wants. Decimal-to-time decodes a stub figure like 7.92 back into hours and minutes you can picture. Both directions round sensibly and show the exact math, so you can check the conversion instead of trusting it blindly.
Choose the direction: time to decimal for filling in timesheets, decimal to time for reading pay stubs.
Enter your hours and minutes, or your decimal figure, then hit Convert.
Read the result plus the exact fraction, so 20 minutes shows as 0.33 with the repeating decimal explained.
The Conversion Math
One division does the whole job. Minutes become a fraction of an hour by dividing by 60, and the fraction reverses by multiplying by 60. The quarter hours are exact: 15, 30, and 45 minutes convert to 0.25, 0.50, and 0.75 with no rounding at all. Everything else is approximate at two decimals, which is the timesheet standard.
Worked example, verified both ways: 7 hours 45 minutes. Forward: 45 Γ· 60 = 0.75, so 7.75 hours. Reverse: 0.75 Γ 60 = 45 minutes, back to 7:45. A messier one: 2 hours 20 minutes. Forward: 20 Γ· 60 = 0.333..., reported as 2.33 hours. Reverse from 2.33: 0.33 Γ 60 = 19.8, rounded to 20 minutes. The round trip survives because the rounding is consistent.
The Quarter-Hour Cheat Sheet
Tape this to your monitor until it is muscle memory. On the minute side: 15 is 0.25, 30 is 0.50, 45 is 0.75. On the decimal side: 0.25 is 15, 0.50 is 30, 0.75 is 45. The thirds: 20 minutes is 0.33, 40 minutes is 0.67. The sixths: 10 minutes is 0.17, 50 minutes is 0.83. The tenths, beloved by lawyers who bill in six-minute increments: 6 minutes is 0.10, 12 is 0.20, 18 is 0.30, 24 is 0.40, 36 is 0.60, 42 is 0.70, 48 is 0.80, 54 is 0.90. With those memorized, you will convert faster than you can open the calculator.
Why Payroll Insists on Decimals
Money math needs one number per line. Multiplying an hourly rate by 7 hours 30 minutes is not defined until you convert; multiplying by 7.5 just works. That is the entire reason timesheets, payroll exports, and freelance invoices speak decimal. The same logic runs project estimates: 120.5 hours at $85 an hour is one multiplication. Rounding enters because payroll systems store two decimals, so 20 minutes becomes 0.33 and the penny differences wash out across a pay period. If your stub shows a total that looks a few cents off from your own math, the rounding of each line is almost always the explanation, not an error.
Tips for Clean Timesheets
Convert at the end, not line by line, when you want the total to reconcile; converting each entry first and then adding can drift by a cent or two from converting the grand total. Keep the same decimal places everywhere: two for payroll, usually two for invoices. Write the original hours and minutes next to the decimal on paper timesheets so a reviewer can verify without a calculator. And learn your employer's rounding boundary before your first disputed stub. A policy that rounds 7:53 to 8:00 is generous; one that rounds it to 7:45 every time deserves a question. The math is neutral. The policy is where the money moves.
Worked Example: The Freelancer's Invoice
Four tasks: 1 hour 25 minutes, 40 minutes, 2 hours 10 minutes, 55 minutes. Convert: 25 / 60 = 0.42, so 1.42; 40 / 60 = 0.67; 10 / 60 = 0.17, so 2.17; 55 / 60 = 0.92. Total: 1.42 + 0.67 + 2.17 + 0.92 = 5.18 hours. At $85 an hour: 5.18 x 85 = $440.30. Line items with both formats, 1:25 (1.42h), keep the invoice transparent and the client dispute-free.
Round each line to two decimals before adding, not after: per-line rounding matches how payroll and accounting systems process the numbers, and it keeps the invoice total reproducible if anyone rechecks the math.
Decimal Hours in Spreadsheets: The SUM Trap
Spreadsheets store times as fractions of a day, so 6:00 AM is 0.25 and noon is 0.5. Summing a column of durations gives a time value, not decimal hours: multiply the sum by 24 to get billable hours. The classic trap is formatting: a total of 27.5 hours displays as 3:30 (27.5 mod 24) unless the cell uses the [h]:mm format, which allows hours past 24.
The safe pattern: enter durations as decimal hours directly (7.75, not 7:45), sum normally, and skip the time formatting entirely. Decimal hours add, multiply by rates, and export cleanly. Reserve hh:mm for display only, converted at the last step. The converter bridges the two worlds; pick one world for the spreadsheet and stay in it.
Why 1.5 Hours Is Not 1 Hour 50 Minutes
The most common time-conversion error is reading the decimal as minutes: 1.5 hours is 1 hour and 30 minutes, not 1 hour 50 minutes, because the .5 is half of 60. The errors get worse with odd decimals: 2.75 hours is 2 hours 45 minutes, and 1.33 hours is about 1 hour 20 minutes. The safe method is always multiply the decimal by 60: 0.75 Γ 60 = 45. Going the other way, divide minutes by 60: 50 minutes Γ· 60 = 0.83 hours. The calculator above does both directions, which is worth using until the multiplication becomes reflex.
The 40-Hour Week in Decimals
Payroll lives in decimals, so learn the landmarks. A standard 40-hour week is 40.0; a 37.5-hour week (7.5-hour days) is 37.5, written 37:30 on the clock. Common day lengths: 8 hours = 8.0, 7.5 = 7.5, 8.5 = 8.5. Overtime math gets easier in decimals too: 43.25 hours at time-and-a-half is 40 + (3.25 Γ 1.5) = 44.875 paid hours, no minute-borrowing required. If your timesheet shows 8:45 and payroll wants 8.75, the calculator's decimal output is the number to submit; rounding it to 8.8 yourself is how small errors compound across a year.
Minutes to Decimals: The Division Trick
Memorize the six minute-values you will use forever: 10 minutes = 0.167, 15 = 0.25, 20 = 0.333, 30 = 0.5, 45 = 0.75, and 50 = 0.833. Everything else is arithmetic from there: 1 hour 40 minutes is 1 + 0.667 = 1.667 hours. For billing in 6-minute (0.1 hour) increments, the legal standard, round minutes to the nearest 6: 1 hour 38 minutes bills as 1.6, 1 hour 41 minutes as 1.7. Enter any HH:MM above and the calculator returns the decimal; check your memorized values against it until you stop needing to.
Decimal Time: The Revolution That Failed
In 1793, revolutionary France tried decimal time: 10 hours per day, 100 minutes per hour, 100 seconds per minute. It lasted about a year. The math was cleaner but every clock in the country became obsolete overnight, and people refused. The lesson for timesheets: decimals are a compromise, not a conquest. We kept the ancient 60-minute hour and bolted decimals onto payroll, which is why this converter exists at all.
Frequently Asked Questions
How do you convert 2 hours 30 minutes to decimal hours?
Divide the minutes by 60 and add: 30 Γ· 60 = 0.5, so 2 hours 30 minutes is 2.5 hours. The calculator above does both directions instantly, including the tricky values like 20 minutes (0.33) and 45 minutes (0.75).
What is 7 hours 45 minutes in decimal?
7.75 hours. 45 Γ· 60 = 0.75 exactly, so this one is clean. Quarter hours are the easy cases: 15 minutes is 0.25, 30 is 0.5, 45 is 0.75. Memorize those three and half of timesheet math disappears.
How do I convert decimal hours back to minutes?
Multiply the decimal part by 60. For 8.6 hours: 0.6 Γ 60 = 36 minutes, so 8 hours 36 minutes. Switch the calculator to decimal-to-time mode and it does this with proper rounding to the nearest minute.
Why do timesheets use decimal hours?
Payroll software multiplies hours by pay rates, and decimals multiply cleanly while hours-and-minutes do not. You cannot multiply $22.50 by 7 hours 30 minutes without converting first, but 22.50 Γ 7.5 is trivial. Decimals are the language of payroll math.
What is 1 hour 20 minutes as a decimal?
1.33 hours. 20 Γ· 60 = 0.333..., rounded to two decimals. These repeating decimals are why timesheets show numbers like 1.33 and 2.67: they are 20 and 40 minutes wearing a decimal disguise.
How does quarter-hour rounding work?
Many employers round clock times to the nearest 15 minutes: 7, 22, 37, and 52 minutes past the hour are the boundaries. A 7:53 clock-in may round to 8:00. Rounding policies must average out fairly over time rather than always favoring the employer. Check your handbook for the exact rule.
Is 0.5 hours 30 minutes or 50 minutes?
30 minutes. The classic beginner mistake is reading 0.5 as 50 minutes because 50 looks like half of 100. But an hour has 60 minutes, so half is 30. When in doubt, multiply by 60: 0.5 Γ 60 = 30.
How do I add decimal hours together?
Add them like ordinary decimals: 7.5 + 8.25 = 15.75 hours. Convert back at the end if you want hours and minutes: 0.75 Γ 60 = 45, so 15 hours 45 minutes. Never add the minute parts as if they were decimals.
What decimal is 5 minutes?
0.08 hours (5 Γ· 60 = 0.0833...). Small minute values produce small decimals that look like rounding errors on timesheets, which is why many workplaces set a minimum billing increment like 6 minutes (0.1 hours) or 15 minutes (0.25 hours).