The Complete Guide to Excel Time Conversion
Excel is powerful, but its handling of time values can be frustrating for payroll managers. If you try to multiply a cell showing "8:30" by an hourly rate of $20, you might get a result of $7.08 instead of $170.00. This happens because Excel stores time as a fraction of a day.
The Golden Rule
In Excel logic, 1.0 = 24 Hours. Therefore, 12 hours = 0.5, and 1 hour = 0.04166.
Method 1: The Multiplication Method (Best for Payroll)
This is the most common method used by accountants. Since Excel stores time as a "Day Fraction," multiplying that fraction by 24 gives you the hours.
- Click the cell where you want the decimal result.
- Type
=(A1)*24(assuming A1 has your time). - Press Enter.
- Important: Right-click the cell, select Format Cells, and choose Number (2 decimal places).
Method 2: The CONVERT Function
If you prefer using built-in Excel functions, the CONVERT function is cleaner to read.
=CONVERT(A1, "day", "hr")
This tells Excel specifically to take the value in A1 (which it sees as a 'day' fraction) and convert it into 'hr' (hours).
Method 3: Extracting Minutes Only
Sometimes you only need the minutes converted to a decimal (e.g., converting 45 minutes to 0.75). Use this logic:
- Formula:
=MINUTE(A1)/60 - Use Case: Great for adding minutes to a whole number of hours manually.
Troubleshooting Common Errors
Problem: Result looks like a date
You typed a formula but got "1/0/1900 12:00".
Fix: Change the cell format from "Time" to "General" or "Number".
Problem: Total hours are wrong
Summing hours > 24 resets to 0?
Fix: Use the custom format [h]:mm to allow totals higher than 24 hours.
Frequently Asked Questions
Why does Excel turn my numbers into dates?
Excel stores dates as serial numbers. Number 1 is Jan 1, 1900. If your calculation results in "1.5", and the format is set to Date, Excel shows "Jan 1, 1900". Always switch Format to 'Number'.
How do I calculate overtime in Excel?
Once you convert time to decimal (e.g., 45.5 hours), use this formula: =IF(A1>40, (A1-40)*1.5*Rate, 0).
Disclaimer: MyShiftCalc is an independent tool and is not affiliated with Microsoft Corporation.