Calcs4All

APR 23 · 2026

Time duration calculator

Measure elapsed time between two clock times, including overnight spans.

What this calculator covers

Use this time duration calculator to measure the elapsed time between a start and end clock time.

The explanation keeps the minute conversion, overnight rule, and final hour total visible so the span is easy to check before using it elsewhere.

Frequently asked questions

How does the overnight option work?
When the end time is earlier on the clock than the start time — for example, 23:00 to 07:00 — toggle the "end time is on the next day" option. The calculator adds 24 hours to the end total before subtracting, giving the correct elapsed time across midnight.
Why is the result shown in both minutes and decimal hours?
Minutes are exact and easy to verify against a clock, while decimal hours are convenient for payroll calculations and schedule comparisons. Both are shown so you can use whichever fits your workflow.
Does the calculator account for breaks or unpaid time?
No. It measures raw elapsed time between the start and end clock times only. To get net paid time, subtract any break duration from the result manually.
What input format does the calculator accept?
Hours and minutes are entered as separate whole-number fields on a 24-hour clock, so 2:30 PM is entered as hour 14, minute 30.

Tool

Run the calculation

RESULT · DURATION

â„–064

Primary result

8.75 hours

From 8:30 AM to 5:15 PM, the elapsed time is 8 hours and 45 minutes (8.75 hours).

Elapsed duration
8 hours and 45 minutes
Total minutes
525 minutes
Decimal hours
8.75 hours

Step-by-step solution

  1. 1.Convert both clock times to minutes after midnight and treat 5:15 PM as the same day.
  2. 2.Subtract the start total from the end total to get 525 minutes of elapsed time.
  3. 3.Convert the minute total to decimal hours so the result is easy to use in schedules or payroll checks: 8.75 hours.

Walkthrough

Visual walkthrough

Clock spans are easiest to verify when both times are converted into total minutes first.

  1. 01

    Translate each clock time into minutes

    8:30 AM → start total, 5:15 PM → end total

    Minute totals make the subtraction deterministic even when the clock labels differ in format.

  2. 02

    Apply the overnight rule if needed

    Same-day subtraction

    If the end time belongs to the next day, a full day is added before subtracting.

  3. 03

    Keep the result in both forms

    525 minutes = 8.75 hours

    Minutes are precise for schedules; decimal hours are convenient for comparisons and downstream payroll math.

    8 hours and 45 minutes