How do I calculate hours for an overnight shift that crosses midnight?

When the end time is earlier than the start time (for example 22:00 to 06:30), you add 24 hours before subtracting. This tool's 'auto' overnight handling does that for you, so 22:00 to 06:30 correctly returns 8 h 30 min instead of a negative number — the most common manual error.

How do I convert hours and minutes to decimal hours?

Decimal hours equal total minutes divided by 60, not the minutes moved after a decimal point. So 7 h 30 min is 7 + 30/60 = 7.50 hours, not 7.30. This calculator shows the decimal-hour figure automatically for payroll and timesheets.

Does the tool subtract my lunch break?

Yes. Enter the unpaid break in minutes and it is subtracted from the gross span to give net worked time. If the break is longer than the shift, the result is clamped to zero and a warning is shown so you never get a negative duration.

What is the 7-minute rule for payroll rounding?

The 7-minute rule rounds time to the nearest quarter hour: 0 to 7 minutes into a 15-minute block rounds down, 8 to 14 rounds up. It is exactly round-half-up to the nearest 15 minutes. FLSA also permits rounding to 5 minutes or to 6 minutes (one tenth of an hour), as long as rounding stays neutral over time and does not systematically favor the employer.

Is the time duration calculator free?

Yes — 100% free. Everything is calculated privately in your browser; no times are transmitted or stored.

Time Duration Calculator

Q: How do I calculate hours between two times?

Convert each clock time to minutes-since-midnight, subtract start from end, then subtract any break. This free calculator does it instantly and shows the result as hours and minutes (e.g. 7 h 30 min), decimal hours for payroll (7.50), and total minutes (450).

Hours & minutes between two times — handles overnight shifts, breaks & payroll decimals.

Start time (24-hour)

When the shift or period begins, e.g. 09:00.

End time (24-hour)

When it ends, e.g. 17:00. Earlier than start = overnight.

Break / lunch (minutes)

Unpaid time to subtract.

Crosses midnight

Auto handles shifts past midnight (e.g. 22:00 → 06:00). Use "Yes" only for a full 24-hour span where start equals end.

Rounding rule

For payroll compliance — FLSA permits 5, 6, or 15-minute rounding. Most users should keep this on exact.

Net duration

—

Time Duration Calculator — guide & how to use

Clock-time elapsed only. This tool computes the elapsed clock time between two times of day on a single day (or one midnight crossing). It does not account for calendar dates, multi-day spans, or Daylight Saving Time changes — on a DST "spring forward" or "fall back" night the real elapsed time differs by ±1 hour from the clock-time difference. Rounding options reflect FLSA-permitted increments and are informational, not legal advice. All math runs in your browser — no times are sent anywhere.

What it does

The Time Duration Calculator tells you exactly how many hours and minutes fall between a start time and an end time. It subtracts your unpaid break, automatically handles shifts that cross midnight, and shows the result three ways: H h M min, decimal hours for payroll, and total minutes. Optional payroll rounding is available.

Worked example

A shift runs from 7:30 to 16:30 with a 30-minute unpaid lunch:

Gross span = 16:30 − 7:30 = 9 h 0 min (540 minutes).
Net worked = 540 − 30 break = 510 minutes = 8 h 30 min.
Decimal hours = 510 ÷ 60 = 8.50 hours (not 8.30 — decimal is minutes divided by 60).

An overnight example: 22:00 to 06:30 with no break. Because the end is earlier than the start, the tool adds 24 hours: (06:30 + 24h) − 22:00 = 8 h 30 min, instead of a negative result.

How to use it

Enter the start and end times in 24-hour HH:MM format (leading zeros are optional — 9:00 and 09:00 are the same).
Add any unpaid break in minutes (leave 0 if none).
Leave crosses midnight on Auto for normal shifts; force Yes only for a true 24-hour shift where start equals end.
Pick a rounding rule if your timesheet requires one — otherwise keep it on exact.
Read the net duration, decimal hours, and total minutes. Use Copy result or Copy share link to keep it.

How the math works

Each clock time is converted to minutes-since-midnight (hour × 60 + minute). The gross span is end − start; if the end is at or before the start under "auto" overnight (or you force "yes"), 1440 minutes (24 hours) are added first. Net worked time is gross minus break, clamped at zero so it never goes negative. Decimal hours are minutes ÷ 60 rounded to two decimals; the underlying minute count stays exact. Optional rounding snaps the net minutes to the nearest 5, 6, or 15-minute increment using round-half-up.

Accuracy notes & assumptions

Single day or one midnight crossing. Spans beyond 24 hours are out of scope for a two-clock-time tool — use a date-and-time calculator for multi-day spans.
Equal start and end on "auto" returns 0, not 24 hours. A genuine 24-hour shift requires setting crosses-midnight to Yes.
No DST adjustment. On clock-change nights the actual worked time differs by ±1 hour.
Break is treated as unpaid time subtracted from the gross span. The tool does not distinguish paid vs unpaid breaks — that is a payroll-policy decision.
Rounding is informational, not legal advice. Under FLSA, rounding must be neutral over time and may not systematically favor the employer; some jurisdictions (e.g. California) now disfavor rounding in favor of actual recorded time. The default is "none" so you see the exact result.
All computation is client-side; no times are transmitted or stored.

Common mistakes this tool prevents

Subtracting clock times directly across midnight (16:30 − 22:00 = negative) instead of adding 24 hours.
Converting minutes to decimal by just moving the decimal point — 7 h 30 min is 7.50, not 7.30.
Forgetting to deduct the lunch break and overstating worked hours.
Faking the break by adjusting the start or end time instead of using a separate break field (which loses audit clarity).

How to embed this tool on your website

No account, no coding. Copy the embed code and paste it where you want it to appear:

<iframe src="https://snaptoolsuite.com/time-duration-calculator/?embed=1"
  style="width:100%;max-width:560px;height:720px;border:0;"
  title="Time Duration Calculator" loading="lazy"></iframe>
<p>Free <a href="https://snaptoolsuite.com/time-duration-calculator/">Time Duration Calculator</a> by Snap Tool Suite</p>

2 Paste it on your page

3 It just works

See it live: view a real embed example →

Frequently asked questions

How do I calculate hours between two times?

Convert each time to minutes-since-midnight, subtract start from end, then subtract any break. The result shows as H h M min, decimal hours, and total minutes.

How does it handle an overnight shift?

When the end time is earlier than the start (e.g. 22:00 to 06:30), it adds 24 hours before subtracting, so you get 8 h 30 min instead of a negative number.

How do I get decimal hours for payroll?

Decimal hours equal total minutes ÷ 60. So 7 h 30 min = 7.50 hours, not 7.30. The tool shows this automatically.

Will it subtract my lunch break?

Yes — enter the unpaid break in minutes. If the break is longer than the shift, the result is clamped to zero and flagged.

What is the 7-minute rule?

It rounds to the nearest quarter hour: 0–7 minutes round down, 8–14 round up. That is exactly round-half-up to the nearest 15 minutes, one of the FLSA-permitted increments alongside 5 and 6 minutes.

Is it really free?

Yes. 100% free, and everything runs in your browser — no times leave your device.

Related tools

Add this calculator to your site

Free to embed on any website, blog, or client portal. One line of HTML — no account, no code, no cost.

<iframe src="https://snaptoolsuite.com/time-duration-calculator/?embed=1"
  style="width:100%;max-width:560px;height:720px;border:0;"
  title="Time Duration Calculator" loading="lazy"></iframe>

2 Paste it on your page

3 It just works

Everything is calculated in your browser. We don't store or sell your data.