Hours and Minutes Worked Calculator

This calculator works out the total time you worked by adding up start and end times for multiple shifts, or by converting hours and minutes into decimal hours for payroll. You enter the start time, end time, and any unpaid break in minutes, and it returns the total hours and minutes worked, plus the decimal equivalent. The first output shows the total duration in hours and minutes (h:mm), which is exactly what you need for timesheets and time tracking.

Formula

The core formula converts clock times to minutes past midnight, subtracts the start from the end, and subtracts any break. In symbols:

Total minutes = (End time in minutes) − (Start time in minutes) − (Break in minutes)

Where:

• Start time and End time are entered as HH:MM on a 24-hour clock (e.g., 14:30 for 2:30 PM). The calculator converts them to minutes past midnight automatically.
• Break is the unpaid rest time in minutes (e.g., 30 for a half-hour lunch).
• Total worked is shown as h:mm (e.g., 8:00 for 8 hours) and also as decimal hours (e.g., 8.00) for payroll or billing.

If the shift crosses midnight (e.g., 22:00 to 06:00), the calculator adds 24 hours (1440 minutes) to the end time, so the math still works.

Worked Example

Using the defaults: Start 9:00, End 17:30, Break 30 minutes.

1. Convert start: 9:00 = 9 × 60 = 540 minutes.
2. Convert end: 17:30 = 17 × 60 + 30 = 1050 minutes.
3. Subtract start from end: 1050 − 540 = 510 minutes.
4. Subtract break: 510 − 30 = 480 minutes.
5. Convert to h:mm: 480 ÷ 60 = 8 hours, 0 minutes → 8:00.
6. Decimal hours: 480 ÷ 60 = 8.00 hours.

So a 9:00–5:30 shift with a 30-minute lunch equals exactly 8 hours of paid work.

Why Use Decimal Hours?

Many payroll systems and billing platforms require time in decimal hours (e.g., 7.5 hours) rather than h:mm (7:30). That is because decimal hours are easier to multiply by an hourly rate. For example, if you earn $20 per hour, 7.5 hours × $20 = $150. If you tried to multiply 7:30 × $20, you would get 150 minutes, which is wrong. This calculator gives you both formats so you can enter the right one into any system.

How to Enter Times Correctly

• Use 24-hour format to avoid AM/PM mistakes: 1:00 PM becomes 13:00.
• Always include the colon: 9:00, not 900.
• If you work overnight, the end time is earlier than the start time (e.g., 23:00 to 07:00). The calculator handles it by adding 24 hours.
• Enter breaks in minutes, not hours. A 45-minute lunch is 45, not 0.75.

Common Mistakes and How to Avoid Them

• Mixing AM/PM: Forgetting that 12:00 is noon and 12:00 AM is midnight. Use 24-hour time to be safe.
• Forgetting breaks: Unpaid breaks must be subtracted. If you skip this, you overestimate pay.
• Rounding too early: If you round to the nearest quarter-hour before calculating, you lose accuracy. Keep full minutes until the end.
• Overnight shifts: Not accounting for the date change. The calculator adds 24 hours automatically, but if you do it manually, remember to add 1440 minutes.

When to Use This Calculator

Use it for:

• Filling out timesheets for an employer.
• Calculating hours for freelance invoicing.
• Tracking how much time you spend on a project.
• Checking that your pay stub matches your actual hours.
• Planning your workday if you have a set number of hours to reach.

It is not a substitute for official time-tracking software, but it is a quick and reliable way to check your numbers.

Limitations of the Formula

The calculator assumes a single start and end time per day. If you have split shifts (e.g., 8–12 and 13–17), you need to add the results of two calculations. It also does not handle overtime rules, holiday pay, or multiple break periods automatically—you would need to adjust the break minutes manually. The formula is pure arithmetic, so it is accurate as long as your inputs are correct.

Frequently Asked Questions

How do I calculate hours worked including lunch break?

Subtract the lunch break from the total time between start and end. For example, 9:00 to 17:30 is 8.5 hours, but if you take a 30-minute lunch, you worked 8.0 hours. Enter the break in minutes (30) and the calculator does the rest.

What if I work overnight, like 10 PM to 6 AM?

The calculator handles it by adding 24 hours to the end time. Enter 22:00 for 10 PM and 06:00 for 6 AM. The result will be 8 hours, minus any break you enter.

How do I convert 7 hours and 30 minutes to decimal?

Divide the minutes by 60 and add to the hours: 30 ÷ 60 = 0.5, so 7.5 hours. The calculator gives you this automatically.

Can I use this for timesheet rounding?

Yes, but you should round after calculating, not before. For example, if you worked 7 hours 52 minutes, you might round to 7.75 or 8.00 depending on your employer’s policy. The calculator gives you the exact figure first.

Why does my pay stub show different hours than I calculated?

Common reasons: unpaid breaks, rounding to quarter-hour increments, or overtime being calculated separately. Check your pay stub policy or ask HR. The calculator gives you the raw worked time, which you can then adjust per their rules.

Is there a way to add multiple shifts in one go?

This calculator handles one shift at a time. To add multiple shifts, calculate each one and sum the totals manually. For example, 4 hours + 3.5 hours = 7.5 hours.

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in t | Start time (HH:MM) | - | 9:00 | 0
in t | End time (HH:MM) | - | 17:30 | 0
in d | Break (minutes) | min | 30 | 0
out duration | Total worked | h:mm | (t2 - t1 - d) | time
out decimal | Decimal hours | h | (t2 - t1 - d) / 60 | 2