Add Time Calculator
Save yourself time and effort and use this add time calculator to automate mundane tasks related to time addition. Have you been asked to calculate your hours and minutes worked? The time addition calculator will do this for you. You can enter up to 20 values in 16 different units!
Read on to learn how to use the time addition calculator and how to add time by yourself.
If you need to add time to a date, count the days between dates, subtract time, or multiply or divide time, then check out the rest of our time calculators.
How to use the add time calculator?
The add time calculator is pretty intuitive. To add up time:

Choose the time unit in the first field. If you want to input hours and/or minutes and seconds, leave the default unit and enter the value. For example, if you want to enter "1 h 50 min", you don't have to change the unit, simply leave the seconds part empty.

Repeat step 1 for all your time values. The new rows will appear as you fill in the last row. You can do the time addition on a maximum of 20 values.

Remember, you can add up time with different units! For example, you can have "55 min" in the first field of the add time calculator and "3 h 23 min" in the second one.

Choose the units of the time addition result. You can change it anytime and use the calculator as a time unit converter.
Note, if you want to go back to the default units, click reset defaults
below the add time calculator.
How to add time without the time addition calculator?
First, you need to know the relationships between different units of time and how to convert between them. Let's list them:

1 year = 365 days
; 
1 leap year = 366 days
;(In the calculators, a year is the averaged number of days  365.25.)

1 month = 28 days
if it's February (29 if in a leap year); 
1 month = 30 days
if it's September, April, June, or November; 
1 month = 31 days
if it's January, March, May, July, August, October, or December;(In our calculators, month = 30.44 days, which is the average across all months.)

1 week = 7 days
; 
1 day = 24 hours
; 
1 hour = 60 minutes
; 
1 minute = 60 seconds
; and 
1 second = 1000 milliseconds
.
Adding time is like adding other numbers, just remember that some units, like seconds, need 60 (instead of 100) to upgrade into a bigger unit.
Let's start with adding time values which involve just one unit.
Add days, add minutes, add up time
Adding time which involves one unit is no rocket science. You need to add all the values and possibly change the unit to a more convenient one. Let's go through some examples.
Add days
Let's say you want to find the days left until your birthday. Today is 11.12.2020, and you'll celebrate it on 3.03.2021. Let's go month by month and count days.

December has 31 days. It's 11th, so in this month you'll have to wait
31  11 = 20
days (not counting 11.12). 
You'll wait the whole of January and February. January has 31 days, February has 28 days. We can add days straightaway:
31 + 28 = 59
. 
Your birthday is on the 3rd of March, so we have 2 days left.

Let's add days from steps 13:
20 + 59 + 2 = 81
. There are 81 days left until your birthday.
Add minutes
You have a couple of tasks to do and want to know how long they will take you in total. You have to do the laundry (15 minutes), study English for tomorrow's test (45 minutes), and adjust your desk's height (15 minutes). To add time together:

Add all the values:
15 + 45 + 15 = 75
. 
The result may be more intuitive if you convert it. There are 60 minutes in an hour, so:
75 / 60 = 1 R 15
,where "R" stands for the "remainder". The final result is therefore:
75 min = 1 h 15 min
Let's add time together
Calculate hours and minutes worked
You want to calculate hours and minutes worked this week: 5 h 30 min, 6 h 15 min, 4 h 45 min, 5 h 55 min, 7 h 35 min. How to add up time in this case?
 Add time together  minutes to minutes, hours to hours, and seconds to seconds:
hours = 5 h + 6 h + 4 h + 5 h + 7 h = 27 h
minutes = 30 min + 15 min + 45 min + 55 min + 35 min = 180 min
 Convert, where possible:
minutes = 180 min = 3 h
 Add the converted values:
27 h + 3 h = 30 h
It's handy to know how to add time by yourself, but calculating hours and minutes worked is pretty tedious, so you can just take advantage of the blessings of automation and use the calculator 🙂