Excel Formulas You Should Definitely Know:

1. SUM
Formula: =SUM(5, 5) or =SUM(A1, B1) or =SUM(A1:B5)
The SUM formula does exactly what you would expect. It allows you to add 2 or more numbers together. You can use cell references as well in this formula.
The above shows you different examples. You can have numbers in there separated by commas and it will add them together for you, you can have cell references and as long as there are numbers in those cells it will add them together for you, or you can have a range of cells with a colon in between the 2 cells, and it will add the numbers in all the cells in the range.
2. COUNT
Formula: =COUNT(A1:A10)
The count formula counts the number of cells in a range that have numbers in them.
This formula only works with numbers though:
It only counts the cells where there are numbers.
**Learn more about the COUNT function in this on-demand, online course. FREE preview**
3. COUNTA
Formula: =COUNTA(A1:A10)
Counts the number of non-empty cells in a range. It will count cells that have numbers and/or any other characters in them.
The COUNTA Formula works with all data types.
It counts the number of non-empty cells no matter the data type.
4. LEN
Formula: =LEN(A1)
The LEN formula counts the number of characters in a cell. Be careful though! This includes spaces.
Notice the difference in the formula results: 10 characters without spaces in between the words, 12 with spaces between the words.
5. TRIM
Formula: =TRIM(A1)
Gets rid of any space in a cell, except for single spaces between words. I’ve found this formula to be extremely useful because I’ve often run into situations where you pull data from a database and for some reason extra spaces are put in behind or in front of legitimate data. This can wreak havoc if you are trying to compare using IF statements or VLOOKUP’s.
I added in an extra space behind “I Love Excel”. The TRIM formula removes that extra space. Check out the character count difference with and without the TRIM formula.
6. RIGHT, LEFT, MID
Formulas: = RIGHT(text, number of characters), =LEFT(text, number of characters), =MID(text, start number, number of characters).
(Note: In all of these formulas, wherever it says “text” you can use a cell reference as well)
These formulas return the specified number of characters from a text string.RIGHT gives you thenumber of characters from the right of the text string, LEFT gives you the number of characters from the left, and MID gives you the specified number of characters from the middle of the word. You tell the MID formula where to start with the start_number and then it grabs the specified number of characters to the right of the start_number.
I used the LEFT formula to get the first word. I had itlookin cell A1 and grab only the 1st character from the left. This gave us the word “I” from “I love Excel”
I used the MID formula to get the middle word. I had itlookin cell A1, start at character 3, and grab 5 characters after that. This gives us just the word “love” from “I love Excel”
I used the RIGHT formula to get the last word. I had itlookat cell A1 and grab the first 6 characters from the right. This gives us “Excel” from “I love Excel”
7. VLOOKUP
Formula: =VLOOKUP(lookup_value, table_array, col_index_num, range_lookup)
By far my most used formula. The official description of what it does: “Looks for a value in the leftmost column of a table, and then returns a value in the same row from a column you specify…”. ( See the full explanation of VLOOKUP) Basically, you define a value (the lookup_value) for the formula to look for. It looks for this value in the leftmost column of a table (the table_array).
Note: If at all possible use a number for the lookup_value. This makes it a lot easier to make sure the data you are getting back is a correct match.
If it finds a match of the “lookup_value” in the left column of the “table_array” it will return the value in the column you specify using the “index_num”. The “index_num” is relative to theleft mostcolumn. So, if you have the table_index look in column A and you want what is returned to be what’s in column B the “index_num” would be 2 because the leftmost column, column A in this case, is the 1st column in the table array and column B is the 2nd column (hence the 2 for the index number). If you want what is in column C to be returned you’d put 3 for the index_num. The “range_lookup” is a TRUE or FALSE value. If you put TRUE it will give you the closest match. If you put FALSE it will only give you an exact match. I only use FALSE when using the VLOOKUP formula.
Example:
You have 2 lists: 1 with a sales person’s ID and the sales revenue for the quarter. Another with the sales person’s ID and the sales person’s name. You want to match up the sales person’s name to the sales person’s revenue numbers for the quarter. They are all jumbled around so to manually match this, even for a small number of salesmen would leave room for a high margin of error and take a lot of time.
The first list goes from A1 to B13. The 2nd list goes from D1 to E25.
In cell C1 I would put the formula =VLOOKUP(B18, $A$1:$B$13, 2, FALSE)
B18 = the lookup_value (the sales person’s ID. This is a number that appears on both lists.)
$A$1:$B$13 = the “table_array”. This is the area I want the formula to search the leftmost column (column E in this case) for the “lookup_value”. I went to F because if it findsmatchin column E, I want it to return what’s in column F. (The money signs are there so that the table_array will stay the same no matter where the formula is moved or copied to. This is called an absolute reference.)
2 = the index_num. This tells the formula the number of columns away from theleft mostcolumn to return in case ofmatch. So, if you find a match between the lookup_value and the leftmost column of the table array, return what’s in the same row in the 2nd column of the table (the 1st column is always the leftmost column. It starts at 1, not 0).
FALSE= tells the formula I want it to only return the value if it’s an exact match.
I would then copy and paste that formula along all the cells in column C next to the first list. This would give me a perfectly aligned list with the sales person’s ID, sales person’s revenue for the quarter, and the sales person’s name.
In order to get a nice neat list of Sales Person ID, Sales Person Name, and Sales Person Revenue all next to each other I used the VLOOKUP formula to compare1 listto another.