Add and subtract decimal durations
Enter one decimal-hour value per line. A plus sign is optional for additions; a leading minus sign subtracts an adjustment. For example, 8.50 plus 7.75 minus 0.25 totals 16.00 hours. This format is intended for values that are already decimal hours, such as quantities copied from a project report or billing worksheet.
Use a point as the decimal separator. Do not enter a colon in this tool: 7.45 means seven hours and twenty-seven minutes, whereas 7:45 means seven hours and forty-five minutes. If your source uses colons, use the main converter or its Batch tab first. Keeping the source format clear prevents a consistent but misleading result.
Adjust records without losing the sign
Subtractions can represent a corrected entry, a non-billable adjustment, or a removed duplicate. A negative combined total remains visible with its sign. It is a mathematical result rather than a claim about payable wages. Keep the reason for each adjustment in your original records, because this tool only receives the numeric durations you enter.
Empty lines are skipped. A line containing letters, multiple decimal points, or an incomplete sign produces a line-specific error. Copy stays disabled until the list is valid. An entirely blank list shows an empty state rather than zero. For very large totals the tool stops with a range message rather than accepting an unsafe number.
Round after combining entries
Each decimal input is resolved to the nearest whole second once. Signed seconds are then accumulated, and the final total is rounded for display. You can choose two, three, four, or six decimal places. Display precision does not introduce extra measured accuracy if your source entries were already rounded by another system.
For a concrete check, 0.25 hours contributes fifteen minutes and 0.50 contributes thirty minutes, so their combined value is 0.75. Subtracting 0.25 from 1.00 gives the same result. All examples use the shared conversion engine rather than a separate formula embedded in this page. That also keeps the minute reference table consistent with these calculations.
Choose a workflow that matches the source
Use this signed list for decimal adjustments. Use Batch for raw h:mm durations, because it can preserve original inputs alongside exact minutes and export the rows. Use the weekly timesheet when seven separate daily entries are easier to check. Those alternatives help you keep a reliable connection between the displayed total and the underlying source records.
Copy places the displayed total on the clipboard and confirms the action. The result is a duration, not a clock time or a wage amount. To estimate pay, you still need a regular rate and the appropriate overtime rules. The calculation takes place locally in your browser; it does not submit the list or retain a saved history after you leave.
Check adjustments with a simple example
Try two hours minus half an hour before pasting a longer adjustment list. Enter 2.00 on the first line and -0.50 on the second; the combined duration should be 1.50 hours. The minus sign applies to the entire second entry. A blank line is only a separator and contributes no duration. For a correction that changes an existing positive entry, replace that entry rather than leaving both versions in the list.