About Time Duration Calculator
Time duration calculator to find hours, minutes, and seconds between two times. Add or subtract time spans and total multiple time blocks. Free tool for work and study.
How to use
- Enter a start time and end time to calculate the duration between them. The calculator supports both 12-hour (AM/PM) and 24-hour time formats. For overnight shifts, enable the overnight toggle — a start time of 10:00 PM and end time of 6:00 AM correctly calculates as 8 hours.
- Alternatively, add or subtract hours, minutes, and seconds from a starting time to find the resulting time. This is useful for calculating end times: if a meeting starts at 2:30 PM and lasts 1 hour 45 minutes, it ends at 4:15 PM.
- Calculate total hours worked across multiple time entries. Add multiple start/end time pairs for a full day or week of work. The calculator sums all durations and shows the total in hours and minutes, and in decimal hours (7 hours 30 minutes = 7.5 hours) for payroll calculations.
- Convert between time formats: hours and minutes to decimal hours (2:45 = 2.75 hours), or decimal hours to hours and minutes (6.25 hours = 6 hours 15 minutes). Payroll systems use decimal hours while timesheets often use hours and minutes.
- Subtract break times from your work duration. Enter your clock-in, break start, break end, and clock-out times. The calculator automatically deducts the break period. A shift from 8:00 AM to 4:30 PM with a 30-minute lunch break is 8 hours of work, not 8.5.
- Use the results for timesheet entries, payroll calculations, overtime tracking, and project time logging. The decimal hour format integrates directly with most payroll and invoicing systems.
Frequently asked questions
How do I calculate hours worked?
Subtract the start time from the end time. From 9:00 AM to 5:30 PM: convert to 24-hour format (9:00 to 17:30), then subtract: 17:30 - 9:00 = 8 hours 30 minutes. Deduct unpaid breaks: 8h 30m - 30m lunch = 8 hours worked. For overnight shifts (10:00 PM to 6:00 AM): add 24 hours to the end time (6:00 AM = 30:00), then subtract: 30:00 - 22:00 = 8 hours. In decimal format: 8 hours 30 minutes = 8.5 hours, 8 hours 15 minutes = 8.25 hours, 7 hours 45 minutes = 7.75 hours. This calculator handles all these conversions automatically.
How do I convert minutes to decimal hours?
Divide the minutes by 60. 15 minutes = 0.25 hours, 30 minutes = 0.50 hours, 45 minutes = 0.75 hours. Common conversions: 5 min = 0.08, 10 min = 0.17, 15 min = 0.25, 20 min = 0.33, 25 min = 0.42, 30 min = 0.50, 35 min = 0.58, 40 min = 0.67, 45 min = 0.75, 50 min = 0.83, 55 min = 0.92. Payroll systems require decimal hours for calculating pay: 37.75 hours at $25/hour = $943.75. Using hours and minutes (37 hours 45 minutes) requires conversion before calculating pay.
How do I calculate overtime hours?
In most Canadian provinces, overtime begins after 44 hours per week (Ontario, Nova Scotia) or 40 hours per week (BC, Alberta). Track total hours worked each week. If the total exceeds the threshold, the hours beyond it are overtime paid at 1.5x the regular rate. Example: 48 hours worked in Ontario at $20/hour. Regular: 44 hours x $20 = $880. Overtime: 4 hours x $30 (1.5 x $20) = $120. Total: $1,000. Some provinces also have daily overtime thresholds: BC pays overtime after 8 hours in a single day, regardless of weekly totals.
How do I calculate time across midnight?
For overnight calculations, the end time is treated as the next day. From 10:30 PM to 6:15 AM: convert to 24-hour (22:30 to 06:15), add 24 to the end time (30:15), subtract: 30:15 - 22:30 = 7 hours 45 minutes. This calculator handles overnight shifts automatically — if the end time is earlier than the start time, it assumes the shift crosses midnight. For multi-day calculations spanning more than 24 hours, enter the date along with the time.
What is the difference between billable and non-billable hours?
Billable hours are time spent directly on client work that you charge for: project execution, client meetings, deliverable creation. Non-billable hours are time spent on internal activities that are not charged to clients: administrative tasks, marketing, professional development, travel between jobs, and internal meetings. Most professional service firms target 60-75% billable utilization (the ratio of billable to total working hours). At $100/hour with 6 billable hours out of an 8-hour day (75% utilization), your effective daily revenue is $600, not $800. Tracking this ratio helps you price services profitably.
How do I round time for payroll?
Most employers round timesheet entries to the nearest 15 minutes (quarter-hour rounding): 8:07 rounds to 8:00, 8:08 rounds to 8:15, 8:22 rounds to 8:15, 8:23 rounds to 8:30. Some use 6-minute rounding (tenths of an hour): 8:06 rounds to 8:06 (0.1), 8:12 rounds to 8:12 (0.2). The rounding method must be neutral over time — it should round in the employee's favour approximately as often as the employer's. Canadian employment standards require that rounding practices do not systematically shortchange employees. Document your rounding policy in writing.
How many work hours are in a year?
Standard calculation: 40 hours/week x 52 weeks = 2,080 hours. After subtracting typical Canadian statutory holidays (10 days) and vacation (10-15 days): 2,080 - 160 to 200 hours = 1,880-1,920 actual working hours per year. For hourly rate calculations: divide annual salary by 2,080 for the base rate, or by actual working hours for the effective rate. A $60,000 salary is $28.85/hour using 2,080 hours, or $31.25-$31.91/hour using 1,880-1,920 actual working hours. The 2,080 number is standard for salary-to-hourly conversions.
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