Time Calculator & Duration Adder
Add, subtract, and calculate time durations, timesheet hours, and clock times.
- 100% free
- Private in browser
- No signup
- No watermarks
Calculation Results
6h 30m 0s
6.5 hrs
Ready for client invoices & timesheets
390 mins
23,400 total seconds
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About Time Calculator & Duration Adder
Need to add up hours for a project invoice, calculate shift hours with lunch breaks, or figure out what time it will be 3 hours and 45 minutes from now? The Time Calculator on TheToolss gives you three easy calculation modes: an incremental duration adder, a daily timesheet shift calculator with break deductions and decimal hours, and a clock time adjuster. Results update in real-time with clean formatting for payroll and time cards.
How to use Time Calculator & Duration Adder
- Choose a mode: Add/Subtract Durations, Work Timesheet, or Clock Time Adjuster.
- Enter hours, minutes, seconds, or your shift start and end times.
- Instantly see total elapsed time, decimal payroll hours, and exact minute sums.
Key features
- Add and subtract multiple duration rows (hours, minutes, seconds)
- Work shift timesheet calculator with custom unpaid break deduction
- Supports overnight shifts that wrap past midnight automatically
- Converts hours and minutes directly into decimal hours for payroll billing
- Adjusts specific clock times forward or backward with 12h/24h precision
Frequently asked questions
- How do I convert hours and minutes to decimal hours for payroll?
- To convert minutes to decimal hours, divide the minutes by 60. For example, 7 hours and 45 minutes equals 7 + (45/60) = 7.75 decimal hours. The Time Calculator computes this automatically.
- Does the timesheet mode support night shifts past midnight?
- Yes. If your end time is earlier than your start time (e.g. starting at 22:00 and ending at 06:00), the calculator automatically detects that the shift concluded the following day.
- Can I add or subtract negative time durations?
- Yes. In duration mode, you can toggle any row between addition (+) and subtraction (-) to compute net project time.
- Can I calculate the difference between two arbitrary times?
- Yes. Simply switch to the "Work Timesheet" mode, enter your Start Time and End Time, and specify any break deduction.
- Is this time calculator completely free and private?
- Yes. The calculator runs 100% locally in your web browser with zero ads, signups, or server requests.
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