Last Updated: 19/08/2026
If spreadsheets still feel intimidating, this beginner’s tutorial breaks down the six essential LibreOffice Calc formulas and formatting tricks you need to start tracking numbers with confidence – no prior spreadsheet experience required.
In this guide, we’ll walk through building a simple monthly expense tracker from scratch, then use it to answer real questions like “How much did I spend on wages this year?” and “What’s the VAT on this amount?”
Setting Up Your Spreadsheet
Every spreadsheet starts with data. In LibreOffice Calc, open a blank sheet and think about how to lay out your information logically. For this example, the goal is to track monthly business costs across categories like:
- Wages
- Travel costs
- Internet
- Phone
- Office rent
Rather than listing every cost down a single column, it’s more logical to put your time periods (months) down the side and your cost categories across the top. This creates a clean grid: 12 rows (January–December) by however many cost columns you need.
Tip: Format Cells as Currency
Before entering numbers, highlight the cells where cost values will go, right-click, and choose Format Cells. Set the format to Currency (e.g., GBP/£) so every value automatically displays with the correct currency symbol – no need to type “£” manually each time.
1. The SUM Formula (via AutoSum)
Once your data is in place, the first and most useful formula is SUM. Instead of manually adding numbers with a calculator, click into an empty cell below a column of values and use the AutoSum tool (the Σ symbol).
LibreOffice Calc automatically detects the range of numbers above and suggests a formula like:
=SUM(B2:B13)
This means: add every value from cell B2 down to cell B13. Press Enter, and you instantly get a total – for example, £31,500 spent on wages for the year.
Time-saving tip: Select all your cost columns at once before clicking AutoSum, and LibreOffice will calculate totals for every column simultaneously – no need to repeat the process one column at a time.
2. Grand Totals (Summing Across Categories)
Once you have individual totals for wages, travel, internet, phone, and rent, you’ll likely want a grand total – the combined spend across all categories.
Simply select the row of individual totals and run the SUM tool again. This adds all category totals together into one final number. It’s good practice to visually distinguish this figure – for example, highlighting it in a different color (like yellow) so it stands out from the category subtotals.
3. Monthly Totals (Summing Across a Row)
Beyond yearly totals, you can also calculate spend for a specific month by summing across a row instead of down a column:
=SUM(B6:F6)
This adds every cost category for a single month (say, January) into one total.
Pro tip – the fill handle: Once you’ve built this formula for one row, hover over the small black square in the bottom-right corner of the cell (the fill handle). Click, hold, and drag it down through the remaining rows, and LibreOffice automatically adjusts the formula for each month – no retyping required.
To double-check what a formula is calculating, double-click the cell: LibreOffice highlights the exact range of cells feeding into it in blue. Press Escape to exit without changing anything.
4. Custom/Selective Sums
Not every calculation needs to include everything. Sometimes you want to combine specific, non-adjacent cells – for example, adding just the Internet and Phone columns together to create a custom “Media Cost” category.
To do this:
- Click into a new cell and start the SUM formula.
- Click the first cell (e.g., Internet).
- Hold Shift and click the second cell (e.g., Phone).
- Press Enter.
This produces a formula that adds only the selected values (e.g., £45), and you can drag the fill handle down to repeat it for every month.
5. Basic Percentage Calculations (VAT Example)
One of the most practical uses of formulas is calculating percentages – such as working out VAT (Value Added Tax) on a price.
If you have a value in cell F2 and want to calculate 20% VAT on it, the formula is:
=F2*0.2
This tells LibreOffice: take the value in F2 and multiply it by 20%. For a base amount of £100, this returns £20 in VAT.
To get the VAT-inclusive total, simply add the original amount and the VAT figure together using SUM, giving you the full amount including tax (e.g., £120).
6. Adjusting the Percentage Rate
Because VAT rates change over time (the UK, for example, has used 20%, 17.5%, and 15% at different points), it’s useful to know how to adjust the formula:
- 20% VAT: =F2*0.2
- 17.5% VAT: =F2*0.175
- 15% VAT: =F2*0.15
Once this formula is built for one row, drag the fill handle down to instantly calculate VAT (and VAT-inclusive totals) for as many values as you need – whether that’s 10 rows or 10,000.
Why This Matters
These six formula concepts – SUM, AutoSum across columns, row totals, custom/selective sums, percentage formulas, and adjustable rates – form the foundation for almost every spreadsheet task you’ll encounter, from tracking business expenses to managing invoices and calculating tax owed to customers.
Once you’re comfortable with these basics, you’ll be able to build spreadsheets that update automatically as you add new data, saving hours compared to manual calculation.
Final Thoughts
This tutorial covers the essentials, but it’s just the beginning of what LibreOffice Calc can do. Practice building your own expense tracker, experiment with different formulas, and get comfortable dragging fill handles to replicate calculations quickly.
Stay tuned for more advanced LibreOffice Calc tutorials covering deeper spreadsheet functionality – and check out related guides on OpenOffice and Microsoft Excel as well.
