Microsoft Excel: The 15 Essential Functions to Master in 2026

Microsoft Excel is the most widely used spreadsheet in the world. Yet the vast majority of users tap into only a fraction of its capabilities. Whether you’re a student, an accountant, an entrepreneur or an analyst, mastering the right Excel functions literally transforms your productivity.

This guide presents the 15 most useful Excel functions in 2026, with concrete examples and real-world use cases. From beginner to advanced, you’re bound to find functions you’re not using yet — and that will change your life.

Contents

• 1. The 5 essential basic functions
• 2. The 5 intermediate functions that make the difference
• 3. The 5 advanced functions that impress
• 4. Bonus tips to work faster
• 5. Which version of Excel should you choose?
• 6. Frequently asked questions

1. The 5 essential basic functions

1. SUM — Add up values

The most used function in Excel. It adds up a range of cells.

=SUM(A1:A10) → Adds up all the values from A1 to A10

Tip: the shortcut Alt + = automatically inserts a SUM formula on the selection. It’s the number 1 Excel shortcut to know.

2. AVERAGE — Calculate an average

Calculates the arithmetic mean of a range of values.

=AVERAGE(B2:B50) → Average of grades, sales averages, etc.

Useful variant: AVERAGEIF calculates the average only of cells that meet a condition. For example: =AVERAGEIF(A2:A50,"London",B2:B50) calculates the sales average for London only.

3. COUNTIF — Count by criteria

Counts the number of cells that match a given criterion.

=COUNTIF(C2:C100,"Paid") → Counts how many invoices have the status “Paid”

=COUNTIF(D2:D100,">1000") → Counts how many amounts exceed 1000€

Use case: invoice tracking, counting orders by status, survey analysis.

4. IF — Conditional logic

The IF function is the brain of Excel. It returns a different result depending on whether a condition is true or false.

=IF(A1>=10,"Passed","Failed")

Nesting: you can nest several IFs to handle multiple cases, but beyond 3 levels, use IFS instead (Excel 2024), which is more readable.

5. CONCATENATE / CONCAT — Join text

Merges several text cells into one.

=CONCAT(A1," ",B1) → Merges the first name and last name with a space

Modern alternative: the & operator does the same thing: =A1&" "&B1. Faster to type.

2. The 5 intermediate functions that make the difference

6. VLOOKUP — Look up a value in a table

The star of Excel functions in business. VLOOKUP looks up a value in the first column of a table and returns the corresponding value from another column.

=VLOOKUP(E2,A:D,3,FALSE) → Looks up the value of E2 in column A, and returns the value from the 3rd column

Concrete example: you have a price table with product references in column A and prices in column C. VLOOKUP lets you type a reference anywhere and instantly get the matching price.

7. XLOOKUP — The modern version of VLOOKUP

Available in Office 2024 and Microsoft 365, XLOOKUP is a clear upgrade over VLOOKUP:

=XLOOKUP(E2,A2:A100,C2:C100,"Not found")

Advantages over VLOOKUP: can look up in any direction (not just left to right), natively handles errors with a “value if not found” parameter, and has a more intuitive syntax. If you have Office 2024, use XLOOKUP across the board.

8. SUMIFS — Multi-criteria conditional sum

Adds up values that match several criteria at once.

=SUMIFS(D2:D100,A2:A100,"London",B2:B100,"2026")

→ Sum of the amounts (column D) only for rows where the city is London AND the year is 2026.

9. TEXT — Format numbers as text

Transforms a number into text with a custom format.

=TEXT(A1,"#,##0.00 €") → Displays “1,234.56 €”

=TEXT(A1,"dddd d mmmm yyyy") → Displays “Monday 6 February 2026”

Use case: create automatic sentences (“Invoice dated Monday 6 February 2026”), format clean exports.

10. PIVOT TABLE

It’s not strictly a function, but it’s the most powerful tool in Excel. A PivotTable instantly summarizes and analyzes thousands of rows of data into a concise summary table.

How to create a PivotTable: select your data → Insert → PivotTable → drag and drop the fields into the Rows, Columns and Values areas.

Example: from a file of 10,000 rows of sales, a PivotTable shows you in 30 seconds your revenue by month, by salesperson, by product — with automatic subtotals.

3. The 5 advanced functions that impress

11. INDEX + MATCH — The ultimate combination

More flexible than VLOOKUP, the INDEX + MATCH combination allows lookups in any direction and across multiple criteria.

=INDEX(C2:C100,MATCH(E2,A2:A100,0))

MATCH finds the position of the value you’re looking for, INDEX returns the value at that position in another column. More complex to write but far more powerful.

12. IFERROR — Handle errors cleanly

Wraps a formula and returns a custom value in case of an error (instead of displaying #N/A or #DIV/0!).

=IFERROR(VLOOKUP(A1,Data,2,FALSE),"Unknown reference")

Essential for dashboards and reports shared with colleagues — nobody wants to see #N/A everywhere.

13. FILTER (Office 2024 / 365)

Dynamically extracts the data that matches a criterion, into a separate range.

=FILTER(A2:D100,C2:C100="London","No results")

→ Automatically displays all the rows where the city is “London”, and updates in real time. It’s a mini database inside an Excel sheet. Available only in Office 2024 and Microsoft 365.

14. UNIQUE + SORT (Office 2024 / 365)

UNIQUE extracts the unique values from a list (removes duplicates). SORT orders them.

=SORT(UNIQUE(A2:A500)) → Sorted list of all the unique values in column A

Perfect for creating dynamic drop-down lists or extracting the unique customers from an order file.

15. LET — Variables inside formulas (Office 2024 / 365)

LET lets you define variables inside a formula, making complex formulas readable and faster.

=LET(total,SUM(A:A),vat,total*0.2,total+vat)

Instead of calculating SUM(A:A) twice, you calculate it once and store it in “total”. On large files, this improves calculation performance.

4. Bonus tips to work faster

Essential keyboard shortcuts

The structured table (Ctrl + T)

Converting your data into a structured table is the most underrated trick in Excel. The benefits are numerous: formulas become readable (instead of A2:A100 you see [ColumnName]), new rows are automatically included, the style is applied automatically, and PivotTables update on their own.

5. Which version of Excel should you choose?

To access all the modern functions (XLOOKUP, FILTER, SORT, UNIQUE, LET), you need at least Excel 2021. For Copilot AI and Python, you need Excel 2024 or Microsoft 365.

6. Frequently asked questions

Which Excel function is the most useful to learn first?

VLOOKUP (or XLOOKUP if you have Office 2024+). It’s the function that saves the most time day to day in business. It eliminates manual copy-pasting between two tables and automates data lookups.

Does Excel Online (free) support these functions?

Most basic functions (SUM, IF, COUNTIF, VLOOKUP) work in Excel Online. But the advanced functions (FILTER, UNIQUE, LET, Power Query) are unavailable or limited. For professional use, the desktop version is essential.

Can Google Sheets replace Excel?

For basic use, yes. But Excel remains superior in terms of performance on large volumes, VBA macros, advanced PivotTables and specialized functions. For a detailed comparison, read our article on alternatives to Microsoft Office.

How do you learn Excel effectively?

The best method is practice on your own data. Take a file from your work and try to solve a real problem with a new function. It’s more effective than any theoretical course.

Is Excel 2024 worth it compared to Excel 2021?

If you use Excel daily, yes. Copilot AI saves you a considerable amount of time creating formulas and analyzing data. And at see price at euroshopkey.com, the upgrade is a minimal investment.

📌 Also read

• Microsoft 365 vs Office 2024: Which to Choose?
• How to Install Office 2024
• Office for Students: Which Version?
• Free Alternatives to Microsoft Office

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