How to Multiply Hours in Excel: Formulas and Formatting

To multiply a duration by a factor in Excel, enter the duration in A2 and the factor in B2, then use =A2*B2. For example, 2 hours 30 minutes multiplied by 1.5 equals 3 hours 45 minutes. Format the result as elapsed time; to calculate a decimal number of hours or pay, multiply the time value by 24 as well.

What You’ll Need

Excel for Microsoft 365 on Windows. The same basic formulas work in Excel for Mac and Excel for the web.
A cell containing an Excel time or duration, such as 2:30 for two hours and 30 minutes, and a cell containing the number or rate to multiply it by.
For pay calculations, an hourly rate entered as a number or currency amount, such as 24 for $24 per hour.

Excel stores time as a fraction of a 24-hour day: one hour is 1/24 of a day. That is why multiplying a time by a factor gives another time value, while multiplying by 24 converts that value to decimal hours. The correct format is just as important as the calculation: a correct result can look wrong if Excel displays it as a clock time or a decimal.

Step-by-Step

Set up your values in separate cells. Put a duration in one cell and the quantity or multiplier in another. For a simple example, type 2:30 in A2 and 1.5 in B2. Excel should recognize 2:30 as a time; if you want to multiply a duration longer than a day, enter its full hours and minutes and use an elapsed-time format. Add clear labels such as Duration and Factor in the cells above your data so you can identify the inputs later.

Be clear about whether the first value is a duration or a decimal number of hours. The entry 2:30 represents two hours and 30 minutes, while 2.5 represents two and a half as an ordinary decimal number. Those values may describe the same amount of time, but Excel stores and displays them differently.
Multiply a duration by a factor. With the duration 2:30 in A2 and the multiplier 1.5 in B2, enter the following in C2:

=A2*B2

The result is 3:45, or three hours and 45 minutes. The arithmetic is 2.5 hours multiplied by 1.5, which equals 3.75 hours; 0.75 hour is 45 minutes. This method is useful for scaling a time estimate, applying a quantity to a task duration, or calculating a longer or shorter duration. Fill the formula down the column to calculate other rows, using the fill handle at the lower-right corner of C2.
Format the result to show elapsed hours and minutes. Select the result cell or result range. On Windows, press Ctrl+1 to open Format Cells, choose the Number tab, select Custom, and enter [h]:mm in the Type box. Click OK. The square brackets tell Excel to show cumulative elapsed hours instead of starting over at zero after 24 hours. On Mac, Command+1 opens Format Cells; choose Custom and enter the same format. Excel for the web supports common time formats, but if its format controls do not offer the custom format you need, open the workbook in the desktop app.

For a result under 24 hours, h:mm may look fine, but [h]:mm is safer for totals. For instance, a duration of 27 hours and 15 minutes displays as 3:15 with a clock-style format, but as 27:15 with the elapsed-time format. The underlying value has not changed; only its display has.
Convert a time value to decimal hours when needed. Suppose A2 contains a duration of 2:30 and you want the answer as a number such as 2.5, not as hours and minutes. Put this formula in B2:

=A2*24

The result is 2.5 because 2 hours 30 minutes is 2.5 hours. Format B2 as General or Number, not as Time. If it still displays as a clock value, select the cell and use Home > Number Format to choose General or Number. This conversion is useful when a report, rate calculation, or other system expects hours as a decimal.
Calculate pay from a duration and an hourly rate. If A2 contains a duration of 2:30 and B2 contains an hourly rate of 24, enter this in C2:

=A2*24*B2

The result is 60, meaning $60 before any other adjustments. The calculation converts the duration to 2.5 hours, then multiplies 2.5 by $24 per hour. Format C2 as Currency or Accounting using Home > Number Format. For a list, keep each duration and rate on the same row, enter the formula in the first result row, then fill it down. If your hours are already entered as a decimal number, such as 2.5 in A2, and B2 contains 24, use =A2*B2 instead; multiplying by 24 again would overstate the amount.
Check that the inputs are really time values. Click a duration cell and look at the formula bar. A displayed value such as 2:30 should be recognized as a time, while a value such as 2.5 is a decimal number. If you are calculating time worked from start and finish clock times, calculate the elapsed duration first, especially when a shift crosses midnight. With a start time of 10:00 PM in A2 and an end time of 6:00 AM in B2, enter this in C2:

=MOD(B2-A2,1)

The result is 8:00, or eight hours. Format C2 as [h]:mm. MOD handles the rollover at midnight, unlike a straightforward subtraction that can produce a negative result. Once you have an elapsed duration, you can multiply it by a factor or convert it to decimal hours as described above.

Common Mistakes

Using clock formatting for a running total. A result greater than 24 hours may display as a smaller time because a clock format wraps around each day. Apply [h]:mm when you need total elapsed hours, for example in a weekly or multi-day total.
Mixing time values with decimal hours. A value entered as 2:30 is stored as a fraction of a day; 2.5 is stored as a number of hours only if you use it that way. Applying the same formula to both without accounting for the difference can produce a result that is off by a factor of 24.
Formatting a numeric answer as a time. A pay result of 60 may show as a date or time if the result cell has inherited a time format. Change the result format to Currency, Accounting, or Number as appropriate. Formatting changes how a value looks, not the underlying calculation.
Typing a multiplier as a percentage incorrectly. If you intend to multiply by 1.5, enter 1.5 or 150%. Entering 1.5% means 0.015, so the resulting duration will be much smaller than expected.
Assuming a time-only entry records a date. A cell containing 8:00 does not tell Excel which day the time belongs to. For ordinary elapsed-time work, that is fine, but a time span spanning midnight needs the rollover calculation shown above or full date-and-time values.

Tips

Use consistent columns: durations in one column, multipliers or rates in another, and results in a third. Clear headings reduce the chance of multiplying the wrong values.
For a whole column of calculations, enter the formula once in the first row and double-click the fill handle to copy it alongside neighboring data. Check the last few rows to confirm the copied references point to the intended cells.
Choose formats based on what the answer means. Use [h]:mm for a duration, Number for decimal hours, and Currency for a money amount. Do not use a currency format for an hourly duration or a time format for pay.
Keep the unrounded calculation in the cell and control the displayed decimals with the Number format when practical. For example, pay may display two decimal places while Excel retains the full underlying value for later totals.
When applying an overtime or adjustment factor, state what the factor represents in a heading or note. A factor of 1.5 means 150% of the original duration or rate; a factor of 0.5 means half. This makes the workbook easier to review.
If you need to total many durations, format the total cell as [h]:mm too. Formatting only the individual rows does not automatically prevent the total from wrapping after 24 hours.

Troubleshooting

The answer looks like a date or a time of day. Select the result cell and change its number format. Use [h]:mm for elapsed hours and minutes, General or Number for decimal hours, and Currency for pay. If changing the format reveals a surprising number, inspect the inputs; the display may have hidden a difference between a time serial and a decimal number.

The answer is 24 times too small or too large. Check whether your duration is stored as a time such as 2:30 or as decimal hours such as 2.5. A duration stored as a time needs conversion to decimal hours before multiplying by an hourly rate. A decimal-hours value does not. Avoid converting the same value twice.

The formula appears as text instead of calculating. Confirm that the cell begins with an equals sign and that the cell format is not Text. Change the format to General, then re-enter the formula by selecting the cell, pressing F2, and pressing Enter. Also check for an apostrophe or leading space before the equals sign.

The result is negative for an overnight shift. A finish time earlier than a start time can produce a negative difference when Excel has no date attached. Use the MOD calculation in Step 6 for a single overnight shift. If the shifts can span multiple days, enter actual dates along with the times so Excel can calculate the full elapsed period correctly.

The displayed total stops at 23:59 and starts over. This is usually a formatting issue, not a failed multiplication. Apply [h]:mm to the result or total cell. If the total still seems wrong, check that the cells being added or multiplied contain numeric time values rather than text imported from another source.

A pasted duration will not calculate. Imported values may be stored as text even when they look like times. Try changing the cell format to Time and re-entering one value manually to compare. If the manual entry calculates but the imported one does not, convert the imported text into a numeric time value before using it in the multiplication.

Frequently Asked Questions

How do I multiply hours by a number in Excel?
Enter the duration and number in separate cells, multiply the cells with the asterisk operator, and format the result as [h]:mm. For example, a duration of 2:30 multiplied by 1.5 gives 3:45.

How do I multiply hours by an hourly rate?
If the hours are stored as a time duration, convert them to decimal hours by multiplying by 24, then multiply by the rate. Format the answer as Currency. If the hours are already a decimal number, multiply that number directly by the rate.

How do I show a result as 2.5 hours instead of 2:30?
Multiply the time serial by 24 and format the result as General or Number. Two hours and 30 minutes becomes 2.5 decimal hours.

Why does Excel show 3:45 as 3:45 AM?
The result cell is likely formatted as a clock time. Choose an elapsed-time format such as [h]:mm to show a duration rather than a time of day.

Can I multiply hours that add up to more than 24?
Yes. Excel can store durations longer than a day. Apply the custom [h]:mm format to show total elapsed hours instead of wrapping back to zero after each 24-hour period.

Does the formula work in Excel for Mac and Excel for the web?
Yes. The multiplication operator and time arithmetic are the same. On Mac, Command+1 opens Format Cells; in Excel for the web, use the available number-format controls or open the workbook in desktop Excel if you need to set a custom elapsed-time format.

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