What this calculator does
Turn hours and minutes into the decimal hours that payroll and invoices use, or back again. Clocks and timesheets show hours and minutes. But payroll systems, invoices and spreadsheets want hours as a decimal number. The two look alike and are easy to mix up: 7 hours 45 minutes is 7.75 hours, not 7.45. Getting it wrong underpays a 45-minute block by almost a third of an hour.
This converter works both ways. Enter hours, minutes and, if you like, seconds to get decimal hours. You'll see the exact answer and one rounded to two decimal places, which most payroll software uses. Or enter a decimal such as 7.8 to see it as 7 hours 48 minutes. A table lists every minute from 1 to 60 as a decimal, for quick lookups when you fill in timesheets.
Where it's used
Why this math matters outside the classroom:
- Timesheets. A shift of 7 hours 45 minutes is 7.75 hours, because 45 ÷ 60 = 0.75.
- Back to minutes. A billing entry of 0.4 hours is 24 minutes, since 0.4 × 60 = 24.
- Payroll. Payroll systems multiply decimal hours by the hourly rate, so 7.75 hours at $20 an hour is $155.
- Billing clients. Freelancers convert time logged in hours and minutes into decimal hours for invoices.
Grade level and standards: Grades 5–6; Common Core State Standards for Mathematics 5.MD.A.1. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.
How to use it
- Choose the direction: hours and minutes to decimal, or decimal to hours and minutes.
- Enter whole hours and minutes (and seconds if you track them), or the decimal hours.
- Read the decimal answer and the one rounded to two places, or the hours-and-minutes answer.
- Use the table to look up single minutes, such as 50 minutes = 0.83 hours.
What the inputs mean
- Minutes
- Whole minutes. Numbers over 59 are fine, so you can enter a total like 135 minutes with 0 hours.
- Seconds
- Optional. Each second is 1/3,600 of an hour, so 36 seconds is 0.01 hours.
- Decimal hours
- Hours with a decimal part, as shown on a pay stub or invoice, such as 7.8 or 38.25.
Formula and method
decimal hours = hours + minutes ÷ 60 + seconds ÷ 3,600 minutes = (decimal hours − whole hours) × 60 seconds = (minutes − whole minutes) × 60
An hour has 60 minutes, so each minute is one sixtieth of an hour. Dividing the minutes by 60 gives the part of an hour they make up. Add that to the whole hours and you have the decimal. Seconds work the same way, with 3,600 in an hour.
Going back, the number before the decimal point is the hours. The part after it, times 60, is the minutes. Any part of a minute left over, times 60, is the seconds. This answer is rounded to the nearest second. That smooths out the rounding in two-place decimals such as 7.33.
Worked example
A timesheet shows 7 hours 45 minutes on Monday and 8 hours 20 minutes on Tuesday. A pay stub later shows 7.8 hours. Convert each.
- Monday: 45 ÷ 60 = 0.75, so 7 + 0.75 = 7.75 hours.
- Tuesday: 20 ÷ 60 = 0.333333, so 8 + 0.333333 = 8.333333 hours, which rounds to 8.33.
- Pay stub: the whole hours are 7, and 0.8 × 60 = 48 minutes.
Result: Monday is 7.75 hours, Tuesday is 8.33 hours (8.333333 exactly), and 7.8 hours is 7 h 48 min.
Understanding the result
Multiply decimal hours by an hourly rate to get pay: 7.75 hours at $18 an hour is $139.50. Multiplying 7.45 instead would give $134.10, which is $5.40 short.
Thirds of an hour never come out exactly in decimals. 20 minutes is 0.3333… hours, so a two-place number (0.33) loses a little each time. Over a week, it rarely changes pay by more than a cent or two. Still, the most accurate way is to add the exact values and round the total once.
Easy ones to remember: 15 minutes = 0.25, 30 minutes = 0.5, 45 minutes = 0.75, 6 minutes = 0.1, 12 minutes = 0.2.
Assumptions and limitations
- An hour has exactly 60 minutes, and a minute has 60 seconds.
- The rounded answer goes to the nearest hundredth of an hour, with halves rounded up.
- It doesn't apply employer rounding rules, such as rounding clock-ins to the nearest quarter hour. Check your workplace policy.
- This converts one amount of time. To get hours worked from start and end times, use the time duration or time card calculator.
Frequently asked questions
How do I convert minutes to decimal hours?
Divide the minutes by 60. 15 minutes is 0.25, 40 minutes is 0.67 (0.6667 exactly), and 50 minutes is 0.83. For hours and minutes together, convert the minutes and add the whole hours.
What is 7 hours 30 minutes as a decimal?
7.5 hours, because 30 minutes is half an hour. In the same way, 8 hours 15 minutes is 8.25, and 6 hours 45 minutes is 6.75.
How do I convert decimal hours back to minutes?
Take the part after the decimal point and multiply it by 60. For 4.6 hours, 0.6 × 60 = 36, so it's 4 hours 36 minutes. For 2.25 hours, 0.25 × 60 = 15, so it's 2 hours 15 minutes.
Why does my pay stub show 7.45 hours when I worked 7 hours 27 minutes?
Because 27 minutes is 0.45 of an hour (27 ÷ 60 = 0.45). Your stub is right. It shows decimal hours, not hours and minutes. Enter 7.45 in the decimal direction to see the conversion.
How this calculator is checked
Method: Definition of the hour: 60 minutes, 3,600 seconds. Decimal = h + m/60 + s/3600; reverse by multiplying the fractional part by 60. The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-18. Found a problem? Tell us.
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