Time calculator: add and subtract hours and minutes

Add and subtract hours, minutes and seconds from a list of durations, with the total as H:MM:SS, decimal hours, minutes and seconds.

হালনাগাদ ২৮ সেপ্টেম্বর, ২০২৬যাচাই করা উদাহরণ: ৪

Total

3 h 35 min 45 s

Total as H:MM:SS: 3:35:45
Decimal hours: 3.5958h
Total minutes: 215.75min
Total seconds: 12,945s

The 3 entries add up to 3:35:45 (H:MM:SS), which is 3.5958 hours or 215.75 minutes.

Each entry in hours

Line by line সারি: ৩

Line	Entry	Seconds	Running total
1	1:45:30	6,330	1:45:30
2	2:20:15	8,415	4:05:45
3	- 0:30:00	−1,800	3:35:45

যেভাবে হিসাব করা হয় S

Convert each entry to seconds
$6{,}330 + 8{,}415 - 1{,}800 = 12{,}945\ \text{s}$
H:MM:SS → 3600 × H + 60 × MM + SS.
Back to hours, minutes and seconds
12,945 s = 3:35:45
Decimal hours
$\frac{12{,}945}{3600} = 3.595833\ \text{h}$

Time calculator: add and subtract hours and minutes সম্পর্কে

Each line is converted to seconds (3,600 × hours + 60 × minutes + seconds), lines that start with a minus sign are subtracted, and the sum is turned back into hours, minutes and seconds. Entries can be written as H:MM:SS, H:MM, 2h 15m, 90 min or 1.5 h. The total is a duration, not a time of day, so 23:59:59 plus one second gives 24:00:00 rather than wrapping to midnight.

Typical uses are adding up timesheet entries, video clip lengths, lap splits and flight legs. The default list, 1:45:30 plus 2:20:15 minus 0:30:00, totals 3:35:45, which is 3.5958 decimal hours or 215.75 minutes.

Decimal hours are the total seconds divided by 3,600, the form payroll and invoicing systems usually ask for: 7 hours 45 minutes is 7.75 hours. To find the time between a start and an end time of day, use the hours calculator instead.

সমাধান করা উদাহরণ

Two additions and a subtraction

Durations, one per line: 1:45:30 2:20:15 - 0:30:00

Total: 3 h 35 min 45 s
Total as H:MM:SS: 3:35:45
Decimal hours: 3.5958 h

যাচাইয়ের উৎস: Python fractions: (6330 + 8415 − 1800) s = 12945 s = 3 h 35 min 45 s; 12945/3600 = 3.5958333…

Carrying past 24 hours

Durations, one per line: 23:59:59 0:00:01

Total: 1 d
Total as H:MM:SS: 24:00:00
Decimal hours: 24 h

যাচাইয়ের উৎস: 86399 + 1 = 86400 s by hand

A negative total

Durations, one per line: 1:00 - 2:30

Total: −1 h 30 min
Total as H:MM:SS: −1:30:00
Decimal hours: -1.5 h

যাচাইয়ের উৎস: 3600 − 9000 = −5400 s by hand

Mixed notations

Durations, one per line: 90 min 1.5 h 45 s

Total: 3 h 45 s
Total minutes: 180.75 min

যাচাইয়ের উৎস: 5400 + 5400 + 45 = 10845 s; 10845 / 60 = 180.75 by hand

প্রশ্ন

How do I add hours and minutes together?

Add the hours and the minutes separately, then carry every 60 minutes into an hour. 1:45 plus 2:20 gives 3 hours and 65 minutes, and 65 minutes is 1 hour 5 minutes, so the total is 4:05. Seconds carry into minutes the same way. Typing each duration on its own line here does the carrying for you.

How do I convert minutes to decimal hours?

Divide the minutes by 60. 15 minutes is 0.25 hours, 45 minutes is 0.75 hours, so 7 hours 45 minutes is 7.75 hours, and 3:35:45 is 12,945 ÷ 3,600 = 3.5958 hours. When a timesheet rounds to two decimals, each 0.01 hour is 36 seconds, so 3.5958 is entered as 3.60.

How do I convert decimal hours back to hours and minutes?

Keep the whole hours and multiply the decimal part by 60 to get minutes. 1.5 hours is 1 hour 30 minutes, 3.6 hours is 3 hours 36 minutes and 0.1 hours is 6 minutes. Type an entry such as 3.6 h on a line here to see it shown as 3:36:00.

How do I subtract one time duration from another?

Start the line with a minus sign. If the minutes to take away are larger, borrow 60 minutes from the hours: 2:10 minus 0:45 becomes 1:70 minus 0:45, which is 1:25. The total can go below zero; 1:00 minus 2:30 gives −1:30:00, an hour and a half short.

How do I add times in Excel without the total resetting at 24 hours?

Excel stores a time as a fraction of a day, so a plain h:mm format wraps after 24 hours and 25 hours shows as 1:00. Format the total cell with the custom format [h]:mm:ss and the square brackets let hours run past 24. To get decimal hours in Excel, multiply the time by 24.

“Time calculator: add and subtract hours and minutes” কতটা নির্ভুল?

নির্ভুলতা আপনার ইনপুট ও পদ্ধতির অনুমানের ওপর নির্ভর করে। দশমিক গণনায় 50টি সার্থক অঙ্ক ব্যবহৃত হয়, কিন্তু আনুমানিক হিসাব, সংখ্যাগত পদ্ধতি ও উৎসের তথ্য কম নির্ভুল হতে পারে; প্রদর্শিত মান রাউন্ড করলে এই সীমাবদ্ধতাগুলি দূর হয় না। স্বতন্ত্র উৎসের সমাধানের সঙ্গে যাচাই করা উদাহরণ: ৪। যেমন, “Two additions and a subtraction” উদাহরণটি Python fractions: (6330 + 8415 − 1800) s = 12945 s = 3 h 35 min 45 s; 12945/3600 = 3.5958333…-এর সঙ্গে যাচাই করা হয়।

এই পদ্ধতির উৎস কী?

ISO 8601-1:2019 — durations and the extended time format hh:mm:ss; BIPM, The International System of Units (SI), 9th ed. — minute and hour as non-SI units accepted for use with the SI.

এই ক্যালকুলেটর সম্পর্কে

T = \sum_i \pm (3600\,h_i + 60\,m_i + s_i)\ \text{s},\qquad \text{decimal hours} = T / 3600

উৎস

ISO 8601-1:2019 — durations and the extended time format hh:mm:ss
BIPM, The International System of Units (SI), 9th ed. — minute and hour as non-SI units accepted for use with the SI

তথ্যসূত্রের সঙ্গে যাচাই করা

এই ক্যালকুলেটরে স্বাধীন উৎস থেকে উত্তর নেওয়া ৪টি সমাধান করা উদাহরণ রয়েছে। এগুলি পরীক্ষার সমষ্টিতে চালানো হয়, আর আপনি এখানেও চালাতে পারেন।