Hours Calculator

Two calculators on this page

They are separate tools, each with its own button and its own answer, so you can use one without clearing the other.

1. Hours Calculator — the hours and minutes between two clock times. Enter a start time and an end time, add any unpaid break in minutes, and press Calculate Hours. Now fills a field with the current time, and Swap exchanges the two.
2. Hours Between Two Dates — the same question when the span runs over more than a day. Give a date and a time for both ends and it reports the whole span, in hours and minutes and also as days.

Use the first for a shift, and the second whenever the two times are not on the same day — or when you are not sure they are, since the first one has to assume.

How the calculation works

The calculator finds the minutes between your start and end times, then subtracts the break. That total is shown two ways: as hours and minutes for reading, and as decimal hours for payroll. If a break is longer than the shift itself, the result is simply zero rather than a negative time.

A worked example

Clock in at 9:00, out at 17:30, with a 45-minute unpaid lunch. The gap is 8 hours 30 minutes (510 minutes); take away 45 minutes and you have 7 hours 45 minutes of paid time, which is 7.75 decimal hours. At $20 an hour that shift is 7.75 × 20 = $155.

Overnight shifts

When the end time is earlier than the start time, the first calculator assumes the shift crossed midnight and adds a day before subtracting. A shift from 22:00 to 06:00 therefore comes out as a full 8 hours, not a negative span, so night and swing shifts need no special handling on your part.

That assumption is the limit of a times-only calculation: it can add one day, never two, so the longest span it can report is 24 hours. When the gap is longer than that — a trip, an on-call rotation, a machine left running over a weekend — the second calculator asks which day each time is on and needs no assumption at all.

Hours between two dates

Give a date and a time for each end and the span is measured exactly. From Aug. 29, 2026, 8:30 AM to Sept. 1, 2026, 5:30 PM is 81 hours — 4,860 minutes, or 3 days and 9 hours. Leap days are counted when they fall inside the span and not when they do not.

The pair is order-independent: putting the later instant first still gives the same length, noted as running backwards rather than treated as an error.

What decimal hours are

Decimal hours express the minutes as a fraction of an hour, which is the format most payroll systems multiply by an hourly rate. Thirty minutes is 0.5, not 0.30. The common conversions:

Minutes	Decimal hour
10 min	0.17
15 min	0.25
20 min	0.33
30 min	0.50
45 min	0.75

How many work hours are in a year?

For standard full-time work at 40 hours a week, the common reference figures are:

Period	Full-time hours (40/week)
Week	40
Month	~173
Year	2,080

Turning hours into pay

To estimate pay, multiply the decimal hours by your hourly rate — 8.5 decimal hours at $20/hour is $170. To convert between hourly, weekly and annual figures, use the salary calculator; to add and subtract spans of time rather than clock times, see the time calculator. This tool is for general timekeeping — always follow your employer's official rounding and timekeeping rules for payroll.