Hours Calculator

What Is an Hours Calculator?

An hours calculator totals up working time from clock-in and clock-out entries — the core of any weekly timesheet. You enter each day's start time, end time, and break length, and it returns the total hours worked for the week, usually in both hours-and-minutes and decimal hours. Freelancers use it for client billing, managers use it to check payroll, and employees use it to verify their payslips.

How It Works

Each day's entry is processed in three steps:

1. Shift duration: end time minus start time (in minutes), adding 24 hours automatically for overnight shifts.
2. Subtract breaks: unpaid meal or rest breaks are deducted from the shift duration.
3. Convert to decimal hours: total minutes ÷ 60. So 7 hours 45 minutes becomes 7.75 hours — the format payroll systems and invoices expect.

Daily totals are then summed for the weekly total. Some versions also split the total into regular hours and overtime hours once a threshold (commonly 40 hours per week) is passed.

How to Use This Calculator

1. For each workday, enter the start time and end time.
2. Enter the unpaid break length for that day (lunch, for example).
3. The calculator shows that day's net hours plus a running weekly total in hours:minutes and decimal form.

Worked Example

Consider a Monday-to-Friday schedule, 9:00 AM to 5:30 PM with a 30-minute lunch break:

• Shift duration: 5:30 PM − 9:00 AM = 8 hours 30 minutes = 510 minutes.
• Minus break: 510 − 30 = 480 minutes = 8.0 hours per day.
• Weekly total: 8.0 × 5 = 40.0 hours.

If Saturday adds a 9:00 AM–1:00 PM shift with no break (4 hours), the weekly total becomes 44 hours — 40 regular plus 4 overtime under a standard 40-hour threshold.

Tips

• Rounding rules: many employers round to the nearest 15 minutes (7-minute rule). Know your workplace policy before disputing a total.
• Paid vs. unpaid breaks: short rest breaks are often paid and should not be deducted; only deduct genuine unpaid meal breaks.
• Keep the raw times: record actual clock times, not pre-rounded ones — rounding each day separately can cost you 15–30 minutes a week versus rounding the weekly total.
• Overtime thresholds: these are set by law or contract and differ by country. In the UAE, for example, overtime rules under the Labour Law differ from the US 40-hour standard — check what applies to you.