30 minutes from now

Adding 30 minutes to a clock time

Add 30 to the minutes. If the total is 60 or more, take 60 away and add one to the hour:

The calculator does this from your device’s current time and marks “next day” when the result passes midnight. It keeps hours and minutes separate, so 9:45 plus 30 minutes is never written as 9:75.

A chain of times from now

Add more rows to the calculator to build a schedule: 30 minutes to finish a task, 45 minutes to travel, 1 hour for a meeting. The result lists the clock time after each step, which answers “when will I be done?” without adding by hand. Type durations the way you think of them — 0:30, 30 min, 1h 15m or 1.5h — and change the start time if you are planning for later rather than now. For the length of time between two clock times, use the time duration calculator; for a work shift with breaks, the hours calculator.

Twelve-hour and 24-hour clocks

The calculator’s start field takes the time on a 24-hour clock, the way phones and schedules often store it — 9:45 p.m. is 21:45 — and shows the answer with a.m. and p.m.: 10:15 PM. Noon is 12:00 and midnight 0:00. On a 12-hour clock the hour after 12:59 p.m. is 1:00 p.m., which is where most mental-math slips happen — 12:45 p.m. plus 30 minutes is 1:15 p.m., not 13:15 p.m. To convert between the two, use the military time converter.

Half an hour in other units

Thirty minutes is half an hour: 0.5 hours on a timesheet, 1,800 seconds, and about 2% of a day’s 1,440 minutes. Billing in tenths of an hour records it as 0.5; billing in quarter hours, as two units of 15 minutes. If a timer or a cooking recipe asks for 30 minutes, the calculator’s end time is the moment to come back.

Time zones and clocks

The answer uses the time zone your device is set to. If you are scheduling for someone elsewhere, convert the end time to their zone: 10:15 p.m. in New York is 7:15 p.m. in Los Angeles. On the two nights a year when clocks change, 30 minutes after 1:45 a.m. may read 2:15, 3:15 or 1:15 depending on the change. To see today’s date and week number, open what is today’s date; for minutes in longer spans, see how many minutes are in a day.