Hours Calculator

Accurately tracking work hours is essential for employees who are paid hourly, freelancers billing by the hour, and managers verifying timesheets.

Manual time card calculations are tedious and error-prone, especially when shifts cross midnight, break times need to be deducted, and overtime thresholds must be tracked.

This hours calculator takes the pain out of timesheet math. Enter your start time and end time for each day, specify any break durations, and the tool calculates your total hours worked in both hours-and-minutes format and decimal hours. It handles AM/PM conversions, overnight shifts, break deductions, and weekly totals automatically.

Whether you are an employee verifying your paycheck, a freelancer preparing a client invoice, or a small business owner processing payroll, this calculator ensures your hour counts are accurate. It converts between clock time (8:30 AM to 5:15 PM) and the decimal hours (8.75) that payroll systems require, and it flags when daily or weekly totals exceed common overtime thresholds.

How to Calculate Work Hours from a Time Card

The basic process for calculating daily work hours is straightforward: subtract your start time from your end time, then subtract any unpaid break time.

Step-by-step:

  1. Convert both times to 24-hour format if needed. 8:30 AM stays 8:30. 5:15 PM becomes 17:15.
  2. Subtract start from end: 17:15 – 8:30. This requires borrowing: 17 hours 15 minutes minus 8 hours 30 minutes. Borrow 60 minutes from the hours column: 16 hours 75 minutes minus 8 hours 30 minutes = 8 hours 45 minutes.
  3. Subtract break time. If you took a 30-minute lunch: 8:45 – 0:30 = 8 hours 15 minutes.
  4. Convert to decimal if needed: 8 hours 15 minutes = 8.25 decimal hours.

For overnight shifts: If you clock in at 10:00 PM and clock out at 6:30 AM, add 24 hours to the end time: 30:30 – 22:00 = 8 hours 30 minutes. This calculator handles overnight shifts automatically.

Understanding Decimal Hours for Payroll

Payroll systems require hours expressed as decimals rather than hours and minutes. This is because multiplying a decimal by an hourly rate is straightforward math, while multiplying hours-and-minutes by a rate requires conversion first.

Conversion method: Divide the minutes by 60 to get the decimal portion, then add it to the whole hours.

Quick reference table:

  • 8 hours 0 min = 8.00
  • 8 hours 15 min = 8.25
  • 8 hours 30 min = 8.50
  • 8 hours 45 min = 8.75
  • 7 hours 20 min = 7.33
  • 7 hours 40 min = 7.67
  • 9 hours 10 min = 9.17
  • 6 hours 50 min = 6.83

Pay calculation example: If you worked 38.75 decimal hours at $22.50/hour, your gross pay is 38.75 x $22.50 = $871.88. If you had converted 38 hours and 45 minutes to minutes first (2,325 minutes), then to hours (38.75), you would get the same result, but the decimal method is far simpler.

Handling Break Deductions

Most employers require an unpaid lunch break for shifts exceeding a certain length. Federal law does not mandate meal breaks, but many states do, and the rules vary.

Common break structures:

  • 30-minute unpaid lunch for shifts over 6 hours
  • Two 15-minute paid rest breaks (typically not deducted from work hours)
  • 60-minute unpaid lunch (some employers)

Paid vs unpaid breaks. Short rest breaks (typically 5 to 15 minutes) are generally considered paid time and should not be deducted from your hours. Meal breaks of 30 minutes or longer are typically unpaid and should be subtracted. The calculator lets you specify the unpaid break duration for each day.

Auto-deduction policies. Some employers automatically deduct a 30-minute break from each shift, regardless of whether the employee actually took one. If your employer has this policy, verify that the auto-deducted hours on your pay stub match your actual worked hours.

Overtime Calculations

Overtime rules determine when an employer must pay a premium rate (typically 1.5x the regular rate) for hours worked beyond a threshold.

Federal overtime rules (FLSA):

  • Non-exempt employees must be paid 1.5x their regular rate for hours worked over 40 in a workweek.
  • The workweek is a fixed, recurring 168-hour period (7 consecutive 24-hour periods).
  • Daily overtime is not required under federal law (but is required in some states).

State-specific rules:

  • California requires overtime for hours worked over 8 in a day, not just over 40 in a week. Double-time is required for hours over 12 in a day.
  • Colorado requires overtime for hours over 12 in a day or 40 in a week.
  • Most other states follow the federal standard of weekly overtime only.

Example calculation: If you work 45 hours in a week at $20/hour in a state following federal rules:

  • Regular pay: 40 hours x $20 = $800
  • Overtime pay: 5 hours x $30 (1.5x) = $150
  • Total gross pay: $950

Weekly Timesheet Example

Here is a practical example of a complete weekly timesheet calculation.

DayClock InClock OutBreakNet Hours
Monday8:00 AM5:00 PM0:308:30
Tuesday8:15 AM5:30 PM0:308:45
Wednesday7:45 AM4:45 PM0:308:30
Thursday8:00 AM5:15 PM0:308:45
Friday8:30 AM3:00 PM0:306:00

Weekly total: 40 hours 30 minutes (40.50 decimal hours)

In this example, the employee worked 30 minutes of overtime (assuming a 40-hour threshold). At $25/hour, the pay calculation would be: 40 x $25 = $1,000 regular + 0.5 x $37.50 = $18.75 overtime = $1,018.75 total.

Rounding Rules for Time Tracking

Many employers round clock-in and clock-out times to the nearest increment, which is legal under federal law as long as the rounding is neutral over time (not systematically favoring the employer).

Common rounding increments:

  • Nearest 6 minutes (1/10 of an hour): Clock in at 8:03, recorded as 8:00. Clock in at 8:04, recorded as 8:06.
  • Nearest 15 minutes (1/4 of an hour): Clock in at 8:07, recorded as 8:00. Clock in at 8:08, recorded as 8:15.
  • Nearest 5 minutes: Clock in at 8:02, recorded as 8:00. Clock in at 8:03, recorded as 8:05.

The 7-minute rule is commonly associated with 15-minute rounding. Times in the first 7 minutes of a quarter hour round down, and times from 8 minutes onward round up. If you clock in at 8:07, it rounds to 8:00. At 8:08, it rounds to 8:15.

Important: Rounding must average out over time. If a rounding system consistently shortchanges employees, it may violate the Fair Labor Standards Act. Employees should verify that rounding does not systematically reduce their hours.

Tips for Accurate Time Tracking

Record times consistently. Write down your clock-in and clock-out times immediately. Memory is unreliable, and reconstructing your hours at the end of the week leads to errors.

Use 24-hour format. It eliminates AM/PM confusion. Writing 17:30 instead of 5:30 PM prevents the possibility of accidentally recording a morning time.

Track breaks separately. Note when your break starts and ends rather than just assuming a standard duration. If you took a 35-minute lunch instead of 30, the 5-minute difference adds up over a pay period.

Compare your records to your pay stub. Calculate your expected gross pay using this hours calculator and compare it to what your employer paid you. Discrepancies may indicate a time tracking error, incorrect rounding, or a payroll mistake.

Keep records for at least 3 years. The FLSA allows employees to file wage claims going back 2 years (or 3 years for willful violations). Keeping your own time records gives you evidence if a dispute arises.

For general time arithmetic (adding hours and minutes without the timesheet context), use the Time Calculator. For date-based calculations, try the Date Calculator.

Frequently Asked Questions

How do I calculate total hours worked from clock-in and clock-out times?

Subtract your start time from your end time, then subtract any unpaid break time. For example, 8:00 AM to 5:00 PM is 9 hours. Minus a 30-minute lunch equals 8 hours and 30 minutes worked (8.50 decimal hours).

How do I convert hours and minutes to decimal hours?

Divide the minutes by 60 and add to the whole hours. For example, 7 hours 45 minutes = 7 + (45/60) = 7.75 decimal hours. Use the quick reference: 15 min = 0.25, 30 min = 0.50, 45 min = 0.75.

How are overnight shifts calculated?

For shifts crossing midnight, add 24 hours to the clock-out time before subtracting. Clock in at 10:00 PM (22:00), clock out at 6:30 AM (6:30 + 24 = 30:30). Duration: 30:30 – 22:00 = 8 hours 30 minutes.

When does overtime start?

Under federal law (FLSA), overtime begins after 40 hours in a workweek for non-exempt employees. Some states like California also require daily overtime after 8 hours. Overtime is paid at 1.5x the regular rate, and some states require double-time for hours beyond 12 in a day.

What is the 7-minute rounding rule?

With 15-minute rounding, times from 1 to 7 minutes round down to the previous quarter hour, and 8 to 14 minutes round up to the next quarter hour. Clocking in at 8:07 rounds to 8:00, but 8:08 rounds to 8:15. This rounding must average out fairly over time.

How do I calculate weekly hours for payroll?

Enter each day’s start time, end time, and break duration. The calculator totals all daily net hours for the week and shows the result in both hours:minutes and decimal format for payroll processing.

Are paid breaks included in total work hours?

Yes. Short rest breaks (typically 5 to 15 minutes) are generally paid and count toward your total hours. Meal breaks of 30 minutes or more are typically unpaid and should be subtracted from your total.

Overtime rules based on current FLSA federal standards. State rules may differ. Data accurate as of: March 2026