AbacusKitCalculators & tools
AbacusKit · https://abacuskit.com/global/hours/ · 2026-10-22

Hours Calculator

Working 09:00 to 17:30 with a 30-minute break is 8 hours a day, or 40 hours over a five-day week. Change the times to see yours.

An end time before the start time means the next day
min
days

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How it works

Enter your start time, end time and unpaid break. The calculator finds the minutes between the two times, takes off the break, and shows the result as decimal hours and as hours and minutes. If the end time is earlier than the start time, it assumes you worked past midnight.

Set the days worked per week to see the weekly, monthly and yearly totals.

Formula and worked example

Hours per day = (end − start − break) ÷ 60, with times in minutes.

For 09:00 to 17:30 with a 30-minute break:

  1. Minutes between the times: 8 × 60 + 30 = 510
  2. Minus the break: 510 − 30 = 480 minutes
  3. In hours: 8
  4. Over five days: 40 hours a week

Frequently asked questions

How do I calculate hours between two times?

Subtract the start time from the end time and take off any unpaid break. From 09:00 to 17:30 is 8 hours 30 minutes; with a 30-minute break that leaves 8 hours.

How do I count a shift that goes past midnight?

Enter an end time that is earlier than the start time. The calculator then treats the end as the next day, so 22:00 to 06:00 is 8 hours.

How do I turn hours and minutes into a decimal?

Divide the minutes by 60 and add the hours. 7 hours 45 minutes is 7 + 45 ÷ 60 = 7.75 hours. The result shows both forms.

What do equal start and end times mean?

Zero hours. If you worked a full 24 hours, set the end time one minute earlier and add the minute yourself.

How are monthly and yearly hours worked out?

Yearly hours are the weekly hours times 52. A month is one twelfth of that, which is about 4.33 weeks, so a 40-hour week is about 173.3 hours a month.

Does it handle different times on different days?

Not yet. It assumes the same hours on every working day. For a week with varying shifts, calculate each pattern and add the results.

Sources and methodology

Last updated 2026-10-20. Calculator version 1.0.0.Read how we calculate for our verification process.

Results are estimates for information only and are not financial, tax or legal advice.