How to Convert 24-Hour Time to 12-Hour Time (Step by Step)

A shift schedule says a warehouse worker starts at 14:00. Read literally, most people can work out that's somewhere in the afternoon — but is it 2 o'clock, or did someone mean 4? The fastest way to remove that doubt is to convert it properly, and the good news is that 24-hour-to-12-hour conversion isn't a judgment call. It's a fixed, mechanical rule with exactly four cases, and once you've done it a dozen times by hand, you'll do it in your head without thinking.

This guide walks through that rule precisely, with worked examples for every case, a shortcut for doing it mentally, and a method for converting a whole list of times at once — in a spreadsheet or by hand. If you already know how the two clocks differ conceptually, the 12-hour vs 24-hour guide covers that ground; this post is purely about the conversion mechanics.

Strip away the cases and there's a single idea underneath all of them: a 24-hour time and its 12-hour equivalent point at the exact same moment. Converting doesn't change when something happens — it only changes how that moment is written down. That means two things stay fixed no matter what: the minutes, and the actual instant in the day. What changes is the hour number (sometimes) and whether you attach AM or PM.

Because the 12-hour clock has no zero and repeats 1 through 12 twice a day, the conversion has to do two jobs at once: fold any hour above 12 back down into the 1–12 range, and attach the correct label so the reader knows which half of the day it fell in originally. Everything below is just that logic applied to four hour bands.

Every 24-hour time lands in exactly one of these four ranges. Find the range, apply its rule, and you're done.

Want the direction filled in for you? The 24-hour to 12-hour converter applies this exact table instantly — type a time, get the answer, no arithmetic required. This section is for when you want to do it yourself, on paper or in your head.

Here's each rule applied to a real time, so you can see the mechanics rather than just the formula.

They don't move — ever. This is the detail people second-guess themselves on most, usually because they've just spent effort adjusting the hour and assume the minutes need the same treatment. They don't. 16:47 becomes 4:47 PM, not 4:12 PM or any other adjusted figure; the 47 carries straight across. The only place minutes get touched is if you're rounding for payroll purposes, which is a separate calculation covered in the timesheet rounding guide — plain time-format conversion never rounds anything.

Once the four-case table is familiar, most conversions take a second or two without writing anything down. Two shortcuts do most of the work:

• For hours 13–19, drop the leading 1 and read the rest as the PM hour: 13→1 PM, 14→2 PM, up to 19→7 PM. It's the same as subtracting 12, but faster to see at a glance.
• For hours 20–23, the pattern shifts to 8–11: 20→8 PM, 21→9 PM, 22→10 PM, 23→11 PM. Memorising this short four-item list removes the need to subtract at all for evening times.

For the two edge hours, skip the math entirely and just remember the label swap: 00 is always 12 AM, and 12 is always 12 PM. Nothing to calculate — those two are pure lookups.

Converting one time is easy by hand; converting a whole timetable is where mistakes creep in, usually because the same case gets applied to every row instead of checking each one individually. Here's a short train timetable converted using the table above, row by row:

Working a list this way — one row, one case check, one result — is slower than eyeballing it, but it's the method that doesn't produce a mislabelled row buried in a longer table. For anything longer than a handful of times, a formula (next section) or the converter removes the risk entirely.

If your 24-hour times live in a spreadsheet, you don't need to apply the rule by hand at all — a display format or one formula handles every row at once. There are two situations, depending on how the times are stored:

If the cell holds a real time value (right-aligned, and you can do time math on it), you only need to change how it's displayed. Select the column, open the custom number format, and enter:

If the cell holds text that looks like a time but isn't a real time value — common when times are pasted from another system as 14:30 — convert the text to a time value first, then format it, in a single formula:

Both work identically in Excel and Google Sheets. Drag either one down a column and every row converts using the same four-case logic covered above — the spreadsheet is just applying it faster than a human can.

• Subtracting 12 from every hour, including morning hours that don't need it. Only 13–23 gets 12 subtracted; 01–11 stays exactly as written.
• Treating 12:00 like the other cases and subtracting 12 from it, which produces 0:00 PM — not a valid 12-hour time. 12:00 never changes its hour.
• Forgetting to add 12 to the midnight hour, so 00:30 is left as "0:30" instead of becoming 12:30 AM.
• Getting the label backwards after doing the arithmetic correctly — subtracting 12 correctly but writing AM instead of PM.
• Adjusting the minutes when only the hour and label were meant to change.

Try feeding it the examples from this page — 00:42, 12:30, 21:58 — and check the result against the worked steps above.