Time to Decimal Calculator

Time to decimal at a glance#

Converting time to decimal turns hours and minutes into a single decimal number of hours, so you can add, multiply or bill it with plain arithmetic. The rule is decimal hours equal whole hours plus the minutes divided by 60. So 2 hours 30 minutes is 2 plus 0.5, which is 2.5 hours.

To convert by hand, divide the minutes by 60 and add the whole hours: for 2 hours 30 minutes, 30 divided by 60 is 0.5, plus 2 is 2.5 hours. Add seconds with the same idea by dividing them by 3600. To go the other way, from decimal back to minutes, multiply the decimal part by 60: 0.75 hours times 60 is 45 minutes, and 0.5 hours times 60 is 30 minutes.

Enter your hours and minutes in the calculator above for the exact decimal result. Values like 0.33 for 20 minutes are rounded, since 20 divided by 60 is 0.3333, so use more decimal places when you need full precision.

The three conversions#

Time to decimal can target three units. Decimal hours is the common one for payroll, but the same idea gives decimal minutes or decimal seconds when you need finer detail.

• Decimal hours = hours + (minutes / 60) + (seconds / 3600)
• Decimal minutes = (hours x 60) + minutes + (seconds / 60)
• Decimal seconds = (hours x 3600) + (minutes x 60) + seconds

Worked examples#

To decimal hours#

Convert 3 hours, 25 minutes, 30 seconds. Take 25 / 60 = 0.4167 and 30 / 3600 = 0.0083, then add to the whole hours: 3 + 0.4167 + 0.0083 = 3.425 hours.

To decimal minutes#

Convert 2 hours, 15 minutes, 10 seconds. The hours give 2 x 60 = 120 minutes, then add 15 and the seconds as 10 / 60 = 0.17: 120 + 15 + 0.17 = 135.17 minutes.

Hours, minutes and seconds at once#

Convert 2 hours, 45 minutes, 45 seconds to decimal hours. The minutes are 45 / 60 = 0.75 and the seconds are 45 / 3600 = 0.0125, so 2 + 0.75 + 0.0125 = 2.7625 hours.

Rounding and precision#

Most conversions are exact, but thirds repeat. 20 minutes is 20 / 60 = 0.3333, which a payroll system usually shows as 0.33. Decide your rounding before you total a timesheet, because dropping a digit on every entry can shift the weekly sum by a few minutes.

Time to decimal FAQ#

Why convert time to decimal at all?#

Decimal hours multiply cleanly against an hourly rate. To pay 7 hours 30 minutes at 20 per hour, you cannot multiply 7:30 by 20, but 7.5 x 20 = 150 works straight away.

How do I convert minutes to decimal?#

Divide the minutes by 60. So 15 minutes is 15 / 60 = 0.25, 45 minutes is 45 / 60 = 0.75, and 50 minutes is 50 / 60 = 0.83.

How do I turn a decimal back into minutes?#

Multiply the decimal part by 60. For 6.75 hours, 0.75 x 60 = 45, so the time is 6 hours 45 minutes. For 3.2 hours, 0.2 x 60 = 12, giving 3 hours 12 minutes.

What are decimal seconds?#

Decimal seconds express the whole duration as seconds. For 1 minute 30 seconds, that is (1 x 60) + 30 = 90 seconds, useful when a calculation needs everything in one unit.

Is this the same as decimal time?#

No. Converting to decimal hours keeps the normal 60-minute hour and just writes the fraction as a decimal. Decimal time was a separate French Revolution idea that split the day into 10 hours of 100 minutes each, and it is not in everyday use.