Hours and Minutes Calculator

total = (hours₁ + hours₂) × 60 + minutes₁ + minutes₂, worked out as one minute count so the addition carries once; the panel then reads that count back as whole hours, the minutes left over, and the same span in minutes

hours1

Whole hours in the first span, with no upper limit — a year of full-time work is around 2000 hours

minutes1

0 to 59. Sixty minutes is one hour and belongs in the hours box, so 90 minutes is entered as 1 hour 30 minutes

hours2

Whole hours in the second span. Set both boxes of one span to zero to add a single duration to nothing

minutes2

0 to 59, under the same rule as the first span — 60 or more is refused rather than carried for you

total

The sum in seconds, and the number the other three rows are read from

hoursPart

Whole hours: 8 h 30 m plus 7 h 45 m is 16. This row keeps counting past a day instead of rolling into it

minutesPart

0 to 59, the minutes left once the whole hours are taken out — 15 in that same sum

totalMinutes

The whole sum counted in minutes: 975, which is 16 × 60 + 15

Use it to add durations that are already written in hours and minutes: two shifts on one timesheet, two legs of a journey, the running length of two recordings, or several jobs quoted in h:mm. It answers one question — how long are these two spans together — so it is not the page for the gap between two clock times, which the time duration calculator works out from a start and an end, nor for turning one span into decimal hours, which is what the time to decimal calculator does. To fold in a third span, add the first two here and put the total into the first box of a second run.

1. Two shifts, 8 hours 30 minutes and 7 hours 45 minutes

   1. Add the minute columns first: 30 + 45 = 75 minutes, which is 1 hour and 15 minutes
   2. Keep the 15 minutes and carry the hour: the hour column becomes 8 + 7 + 1 = 16
   3. The total is 16 hours 15 minutes, which is 16 × 3600 + 15 × 60 = 57600 + 900 = 58500 seconds
   4. In minutes the same sum is 975, and 975 ÷ 60 = 16.25 decimal hours if a timesheet wants it that way

   The carry is the whole point of the page: 30 + 45 minutes is more than an hour, and a calculator that simply wrote 16 hours 75 minutes would be handing back something that is not a time.

2. A carry that lands exactly on the hour

   1. 15 + 45 = 60 minutes, which is exactly one hour with nothing left over
   2. The hour column becomes 1 + 0 + 1 = 2 and the minute column becomes 0
   3. The total is 2 hours, written as 2 hours 0 minutes — there is nothing to show in the minute place
   4. In seconds: 2 × 3600 = 7200, which is also 120 × 60

   A sum that lands on the hour is where a careless implementation shows 2 hours 60 minutes. The minute row reads 0 here because the carry consumed all of it.

3. Past a day, 20 hours plus 5 hours

   1. There are no minutes on either side, so the hour columns simply add: 20 + 5 = 25
   2. The whole-hours row says 25 and the minute row says 0
   3. In the sentence at the top of the panel the same span reads 1 day 1 hour, because the prose form rolls into days past twenty-four hours
   4. In minutes it is 25 × 60 = 1500, and in seconds 1500 × 60 = 90000

   Two readings of one span, both correct: a timesheet needs 25 hours, a person reading the sentence gets a day and an hour. Neither row is the rounded version of the other.

Only two spans fit in the form, and both are typed in whole hours and whole minutes: there is no seconds box, so two durations recorded to the second cannot be added exactly. Minutes are capped at 59 in each box instead of being normalised for you, which keeps the rule identical to the one on the pages that convert a span into decimal hours — the carry is produced by the addition rather than typed in. The prose row rolls into days past 24 hours while the whole-hours row does not, so a 25-hour total reads as 1 day 1 hour in one place and 25 in another. Nothing here deducts a break, applies a rate, or knows about dates and time zones, so two spans either side of midnight add up exactly like two inside the same morning.

How do I add hours and minutes together?

Add the minute columns, and every 60 minutes in the result becomes one hour in the hour column. 45 minutes plus 50 minutes is 95 minutes, which is 1 hour 35 minutes, so the hour column gains one. This hours and minutes calculator does the carry for you: 8 h 30 m plus 7 h 45 m is 16 h 15 m, not 16 h 75 m.

Why can't I type 90 minutes?

Because 90 minutes is not part of a time, it is a carry: 90 minutes is 1 hour 30 minutes, and each box holds a component rather than a running total. Minutes stop at 59 so that a second span of 7 hours 60 minutes is refused instead of being quietly read as 8 hours. Type the carry where it belongs — 1 hour 30 minutes rather than 0 hours 90 minutes.

What is 8 hours 30 minutes plus 7 hours 45 minutes?

16 hours 15 minutes, which is 975 minutes or 58500 seconds. The minute columns give 30 + 45 = 75, which is 1 hour 15 minutes; the hour columns give 8 + 7 = 15, plus the carried hour, which is 16. If a timesheet wants the total as decimal hours instead, 975 ÷ 60 = 16.25.

What happens when the total goes past 24 hours?

The sentence at the top of the panel rolls into days and the whole-hours row does not. 20 hours plus 5 hours reads as 1 day 1 hour in prose and as 25 in the hours row, and the minutes row continues as 1500. Both are honest readings of one span, and they are spelled this way because a payroll line of 25 hours has to stay 25 while a person reading the answer wants a day and an hour.

Is this the same as the time duration calculator?

No — that page starts from two clock times and measures the gap between them, which is what you want for one shift or one meeting. This page starts from durations that are already written in hours and minutes and adds two of them, which is what you want for two shifts or two recordings. Use the time duration calculator when you have a 09:00 and a 17:30, and this one when you already know the spans.

• SP 330, Section 4 — Units outside the SI accepted for use with the SI (Table 8: 1 h = 60 min, 1 d = 24 h) — NIST
• 29 C.F.R. § 785.48 — Use of time clocks (working time recorded and totalled to the nearest tenth or quarter of an hour) — Legal Information Institute, Cornell Law School