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Time Half Calculator

Half Time Calculator works out Duration in hours and Duration in minutes from Durations, A two-part duration like 3:45 means and Number of equal parts. The default figures on this page give duration in hours of 0.5000 h; change any entry and the result, the working and the sources update together.

Duration in hours
0.5000 h
Time Duration Calculator
Duration in minutes
30.00 min
Duration in seconds
1,800 s
Whole days
0 d
Hours part
0 h
Minutes part
30 min
Seconds part
0 s
Duration as h:mm
0:30
Duration as h:mm:ss
0:30:00
Duration in words
30 minutes
Hours after the break
0.5000 h
Break deducted
0 min
Resulting time (24 h)
09:30:00
Resulting time (12 h)
9:30 AM
Days rolled over
0 d
Crosses midnight
no
Durations in the list
1
Average duration
1.0000 h
Duration before splitting or rescaling
1.0000 h
Worked out from ISO 8601-1:2019, Date and time - Representations for information interchange, clauses 5.3 and 5.5 and 2 other sources.

Your figures

Updates as you type
One duration per line, or separated by commas. Write 1:23:45 for hours:minutes:seconds, 90m or 1.5h for a single unit, or 1h 30m for a mixture. A two-part "3:45" is read using the setting below.
Split mode: 2 halves the duration, 3 gives thirds, and so on.
Accepts 09:00, 9:00 am or 09:00:30.
Give both dates for spans longer than a day.

How this is worked out

2 steps
  1. 1:00:00 split into 2 equal part(s) = 0:30:00 each.
  2. 30 minutes total = 0.5 hours (60 s = 1 min, 60 min = 1 h).
Each durationtable
indexclockminuteshours
11:00:00601

Its 10 worked examples are re-run on every release, last on 15 September 2026. What changed

Sources and references

3 sources
ISO 8601-1:2019, Date and time - Representations for information interchange, clauses 5.3 and 5.5
Time-of-day and duration representation: 24-hour clock, sexagesimal minutes and seconds.
BIPM SI Brochure, 9th edition, Table 8 (non-SI units accepted for use with the SI)
1 min = 60 s, 1 h = 3600 s, 1 d = 86400 s - the exact conversions used for the decimal totals.
US Department of Labor, Fact Sheet #22: Hours Worked Under the FLSA
Bona fide meal periods of 30 minutes or more are not work time, which is why the break deduction is separate from the raw span.

What the Half Time Calculator calculates

Elapsed time between two clock times, including overnight and multi-day spans, adding or subtracting hours, minutes and seconds from a time, totalling a list of durations such as a playlist or a set of videos, halving or splitting a duration, and rescaling a runtime for playback speed.

How to use this Half Time Calculator

Enter Durations, A two-part duration like 3:45 means, Number of equal parts and Start time. Duration in hours updates as you type. Change one figure at a time to see what drives the result.

How the result is worked out

Open “How this is worked out” beside the result for the step-by-step calculation behind Duration in hours, Duration in minutes and Duration in seconds.

The method follows ISO 8601-1:2019, Date and time - Representations for information interchange, clauses 5.3 and 5.5, BIPM SI Brochure, 9th edition, Table 8 (non-SI units accepted for use with the SI) and US Department of Labor, Fact Sheet #22: Hours Worked Under the FLSA.

What you can compare

Change one input at a time to see how it affects Duration in hours, Duration in minutes and Duration in seconds. The inputs you can vary are Durations, A two-part duration like 3:45 means, Number of equal parts, Start time, Start date (optional) and End date (optional).

Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.

Embed this calculator on your website

Copy this code into any page. The calculator appears with the figures currently entered, sizes itself to fit, and a small credit line links back here. Free, no account, no ads inside it, no tracking of your readers. Set your own figures and fixed fields; Personal removes the credit line, sets your colour and shows you which sites use it.

Preview

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Frequently asked questions

How do I calculate my time and a half?

Elapsed time between two clock times, including overnight and multi-day spans, adding or subtracting hours, minutes and seconds from a time, totalling a list of durations such as a playlist or a set of videos. Open “How this is worked out” beside the result to see each step for your own figures.

How do I calculate time and a half pay?

It needs Durations, A two-part duration like 3:45 means, Number of equal parts, Start time, Start date (optional) and End date (optional). Nothing else is required, and the figures stay in your browser.

What's time and a half for $20 an hour?

Elapsed time between two clock times, including overnight and multi-day spans, adding or subtracting hours, minutes and seconds from a time, totalling a list of durations such as a playlist or a set of videos. On this page it is computed from Durations, A two-part duration like 3:45 means and Number of equal parts and shown as Duration in hours, Duration in minutes and Duration in seconds.

What information do I need for the Half Time Calculator?

You need Durations, A two-part duration like 3:45 means, Number of equal parts, Start time, Start date (optional) and End date (optional). The page opens with default figures that give duration in hours of 0.5000 h, so you can see the scale before entering your own.

What does this Half Time Calculator show?

It shows Duration in hours, Duration in minutes, Duration in seconds, Whole days, Hours part, Minutes part, Seconds part and Duration as h:mm, with the working and any warnings for your entries.

Can I check how the Half Time Calculator result was calculated?

Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.

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