Digit Sum Calculator
The digit sum calculator enables you to find the total sum of digits in any given set of numbers. You may view the results for each number separately or the entire set of numbers together. The outcome will be displayed as a table of the sum of digits. You also have the option to find the count of digits for the numbers and an example of the sum of digits to see how the calculator works!
What is digit sum?
We can obtain the sum of digits by adding the digits of a number by ignoring the place values. So, for example, if we have the number 567
, we can calculate the digit sum as 5 + 6 + 7
, which will give us 18
.
In this manner, we can find the total sum of the digits of any positive integer, using our digit sum calculator. The calculator also works for numbers of different orders of magnitude.
The sum of digits calculator considers the number of occurrences of each digit in the given numbers. It calculates the partial sum of each digit by multiplying the number of occurrences of the digit and the digit itself. It then adds these partial sums to find the total sum of digits.
You may also input a set of consecutive integers to find the sum of digits in all those numbers! It's also interesting to note that numbers occurring in everyday life tend to follow the Benford's law. We have a dedicated tool if you are curious, check out Benford's law calculator!
How do I calculate the sum of digits of all numbers?
In order to find the sum of digits of the entire set of numbers, here's what you need to do:
 Key in all the numbers into the digit sum calculator (up to 10 numbers).
 Choose the Sum of digits option.
 For the treatment of numbers, choose As a single group.
 Voila! The sum of digits calculator will give you the total sum of all digits across all the numbers that you entered!
But if you're looking to calculate the total sum of the numbers and not just the digits, then you may want to use the addition calculator! Alternatively, you may also try finding the digital root of the numbers!
Sum of digits example
Let's say you want to find the sum of digits in the following numbers:

1111177770999

5555555555

0
After selecting the Sum of digits option, if you choose to treat each number separately, then you'll get the sum of digits as a table, as follows:
For the number 1111177770999:
Digit  No. of occurrences  Sum 

1  5  5 
7  4  28 
0  1  0 
9  3  27 
Total  60 
For the number 5555555555:
Digit  No. of occurrences  Sum 

5  10  50 
Total  50 
For the number 0:
Digit  No. of occurrences  Sum 

0  1  0 
Total  0 
The No. of occurrences column also gives you the count of the number of digits. If you don't have any numbers handy, but you still want to try out this calculator, you may use our random number generator to get some numbers and input them here!
What is digit sum used for?
The most popular applications for the sum of digits lie in finding the divisibility of the given number. Here are a few rules that are based on the sum of digits:

Divisibility by 3 — If the sum of digits of a number is divisible by 3, then that number is also divisible by 3. For example, if we consider the number
123,453
, the sum of its digits is18
, and we can further reduce the sum of digits of18
to9
. Since9
is divisible by 3, this means that123,453
is also divisible by 3; 
Divisibility by 9 — If the sum of digits of a number is divisible by 9, then that number is also divisible by 9. Looking at our earlier example, we can see that
123,453
is divisible by 9 too, since its sum of digits (18 and then subsequently 9) is divisible by 9! 
Digit sums were also used in early computers as a means to check arithmetic or binary calculators.
FAQ
What is the formula for sum of consecutive numbers?
To find the sum of N consecutive numbers, we'll use the formula N × (first number + last number) / 2. So, for example, if we need to find the sum of numbers from 1 to 10, we will have 10 × (1 + 10) / 2, which will give us 55.
What is the sum of digits from 1 to 100?
The sum of all digits of all numbers from 1 to 100 is 901. This is obtained by adding digits 1 through 9 ten times for the units place, followed by adding digits 1 through 9 ten times again for the tens place, and then finally adding the digit 1 that's in the hundreds place of 100.
What is the sum of digits from 1 to 10?
The sum of all digits of all numbers from 1 to 10 is 46. This result is obtained by adding digits 1 through 9 once for the singledigit numbers, followed by adding the digit 1 in the tens place of 10.
What is the sum of digits from 1 to 1000?
The sum of all digits of all numbers from 1 to 1000 is 13,501. This result is obtained by doing the following:
 Add digits 1 through 9 hundred times for the units place.
 Add digits 1 through 9 hundred times again for the tens place.
 Add digits 1 through 9 hundred times again for the hundreds place.
 Finally, add the digit 1 that's in the thousands place of 1000.
 Tada! We'll get the sum of digits of all integers from 1 to 1000 as 13,501!