How Many Hours Between Two Times? A Simple Method

Your shift starts at 22:00 and ends at 06:00. Or a flight boards at 13:50 and leaves at 14:35. Or you started reading at 09:10 and finished at 11:47. Every one of these is the same question wearing a different outfit: how many hours sit between these two clock times? You don't need a calendar app or a spreadsheet to answer it — just one small piece of arithmetic, applied consistently.

This page shows that arithmetic: the exact three steps, worked through on an ordinary pair of times and then on a pair that crosses midnight, which is where most people get tripped up. If you'd rather skip the subtraction, the site's own hours calculator runs the same method instantly. For the fuller breakdown across longer spans, see how to calculate the duration between two times.

Every “hours between two times” question reduces to the same three moves, and none of them need anything more than addition and division.

• Step 1 — convert each time to minutes since midnight. Multiply the hour by 60 and add the minutes. 09:15 becomes (9 × 60) + 15 = 555 minutes.
• Step 2 — subtract the start from the end. Later minus earlier, always.
• Step 3 — divide the result by 60. The whole number is hours; whatever is left over is minutes.

That's the raw hours-and-minutes figure for a single gap. For spans that run across several calendar days rather than a few hours, see how to calculate the duration between two times; for the general rules of adding and subtracting clock values — not just finding a gap — see how to add and subtract time.

Enter a start and end time below — 24-hour format, colon optional — and the count updates as you type.

This is where the shortcut in §1 needs one extra move. If the end time's clock value is earlier than the start time's — 06:00 is “earlier” than 22:00 on the clock face — the gap runs past midnight into the next day, and a plain subtraction gives a negative number that means nothing on its own.

The fix: add 1,440 minutes (24 hours) to the negative result before dividing.

An overnight shift that looks like it runs “backwards” on paper is still an ordinary 8-hour shift — the arithmetic just needs that one adjustment.

“How many hours” can mean two different things depending on who's asking. A friend asking how long a flight is wants a whole number — “about 8 hours.” A timesheet, an invoice, or a billing system wants the exact decimal — 8.50 hours, not “eight and a half.”

To round to the nearest whole hour, look at the minutes: 30 or more commonly rounds up, under 30 rounds down — though for pay purposes, pick one convention and use it consistently rather than switching case by case. For the exact decimal, divide the minutes by 60 instead of rounding: 30 minutes is .50 hours, 15 minutes is .25, 45 minutes is .75. The full minutes-to-decimal-hours conversion is worth bookmarking if you do this often, and most payroll systems apply a rounding rule — commonly the 7-minute rule — before the decimal is calculated at all.

• Work shifts, especially overnight ones that cross midnight.
• Sleep duration — bedtime to wake time (see how sleep cycles work).
• Travel — boarding to departure, or the length of a layover.
• Cooking and baking — a start time to a finish time on a recipe.
• Meetings and calls logged by clock time rather than a stopwatch.

• Subtracting 12-hour AM/PM times directly without converting first — 9:00 AM and 5:00 PM aren't 9 and 5 in this arithmetic. Convert to 09:00 and 17:00 first.
• Forgetting the midnight-crossing adjustment and reporting a negative or wildly wrong number.
• Mixing minutes and decimal hours partway through a calculation — 8:30 is 8 hours 30 minutes, not 8.30 hours. Convert fully before you round.
• Treating an identical start and end time as “24 hours” instead of zero — the same clock time twice, on the same day, is a zero-length gap.