Every Excel formula begins with an equals sign (=). The five basic formulas you'll use most are SUM to add numbers, AVERAGE to find the mean, COUNT to count how many cells hold numbers, MAX for the highest value and MIN for the lowest. For example, =SUM(B2:B10) adds every number from B2 down to B10. Learn these five and you can already build a working salary or marks sheet.
How a formula works
You type a formula into a cell, and the cell shows the answer instead of the text you typed. The real formula stays visible in the Formula Bar. A formula points to other cells by their address, so when those cells change, the answer updates on its own.
A range like B2:B10 means "from B2 to B10, including everything in between." The colon reads as "to".
SUM — add numbers
=SUM(B2:B10)
Adds all the numbers in that range. You can also add specific cells: =SUM(B2,B5,B8).
AVERAGE — find the mean
=AVERAGE(B2:B10)
Adds the numbers and divides by how many there are. Useful for average marks, average daily sales, average attendance.
COUNT and COUNTA
=COUNT(B2:B10) counts cells that contain numbers
=COUNTA(B2:B10) counts cells that are not empty (numbers or text)
Use COUNT to answer "how many students have marks entered?" and COUNTA to count names in a text column.
MAX and MIN — highest and lowest
=MAX(B2:B10) the highest value
=MIN(B2:B10) the lowest value
Handy for top score, highest sale, or the cheapest item.
The AutoSum shortcut
You don't always have to type SUM. Click the cell just below a column of numbers and press Alt + =. Excel guesses the range and writes the SUM formula for you. Press Enter to accept.
Worked example (a simple sales sheet)
| A | B | |
|---|---|---|
| 1 | Day | Sales (₹) |
| 2 | Mon | 4,000 |
| 3 | Tue | 6,500 |
| 4 | Wed | 3,200 |
| 5 | Total | =SUM(B2:B4) → 13,700 |
Add two more formulas below: =AVERAGE(B2:B4) gives 4,566.67, and =MAX(B2:B4) gives 6,500 (the best day).
Quick reference
| Formula | What it does |
|---|---|
=SUM(range) | Adds the numbers |
=AVERAGE(range) | Finds the mean |
=COUNT(range) | Counts number cells |
=COUNTA(range) | Counts non-empty cells |
=MAX(range) | Highest value |
=MIN(range) | Lowest value |
Pro tips
- Select a range of numbers and look at the bottom-right status bar — Excel shows the Sum, Average and Count without any formula. Great for a quick check.
- Type the formula name in lowercase; Excel capitalises it for you if it's spelled right. That's a free spell-check.
- Use AutoSum (
Alt+=) for speed once you understand what it's doing.
Common mistakes
- Forgetting the
=sign. Without it, Excel shows your text as text and does no calculation. - Including the heading in the range.
=SUM(B1:B4)where B1 is "Sales" is fine because text is ignored, but=AVERAGEcounts only numbers, so mixing can confuse you. Start ranges at the first number. - Empty cells in AVERAGE. AVERAGE ignores blank cells but includes zeros. A
0and a blank give different averages.
Key takeaways
- Every formula starts with
=. - SUM adds, AVERAGE means, COUNT counts numbers, MAX/MIN find extremes.
- A range like
B2:B10means B2 to B10. - AutoSum (
Alt+=) writes SUM for you.
Practice task
Open the grocery sheet from the beginners lesson. Below the Price column, write a SUM to get the total bill, an AVERAGE price, and use MAX to find the most expensive item.
These five formulas are day one. To build full reports and dashboards, join the ADCA program at HCI.
Frequently Asked Questions
What are the basic formulas in Excel?
The five basic formulas are SUM (add), AVERAGE (mean), COUNT (count numbers), MAX (highest) and MIN (lowest). Each starts with an equals sign.
How do I use the SUM formula in Excel?
Type `=SUM(` then select the range of numbers, close the bracket and press Enter. Example: `=SUM(B2:B10)` adds everything from B2 to B10.
What is the difference between COUNT and COUNTA?
COUNT counts only cells with numbers. COUNTA counts any cell that isn't empty, including text.
What is AutoSum in Excel?
AutoSum is a shortcut that writes the SUM formula for you. Click below a column of numbers and press `Alt` + `=`, then Enter.
Why is my formula showing as text?
You probably forgot the `=` at the start, or the cell is formatted as Text. Start with `=` and set the cell format to General.