How to update a price list
- List: Choose an Excel (.xlsx) or CSV file, or paste rows copied from a spreadsheet.
- Column: Pick the column that holds the prices and tick the box if the first row is a header.
- Change: Enter a positive percentage for an increase or a negative one for a decrease (for example 7.5 or −5).
- Rounding: Round to the cent, to 1, 5 or 10, or to prices ending in .99.
- Download: Get a CSV with old and new prices side by side; it opens in Excel.
Percentage changes are not additive
Two successive 10% increases make a 21% increase, not 20%: 1.10 × 1.10 = 1.21.
Reversing an increase with the same percentage does not restore the old price. A 20% increase on 1,000 gives 1,200; a 20% decrease then gives 960. To go back, the decrease must be 1 − 1 ÷ 1.20 = 16.67%.
| Rounding | 1,234.56 with an 8% increase |
|---|---|
| To the cent | 1,333.32 |
| To 1 | 1,333.00 |
| To 5 | 1,335.00 |
| To 10 | 1,330.00 |
| Ending in .99 | 1,333.99 |
Frequently asked questions
Is my Excel file uploaded?
No. The file is read and processed in your browser; nothing is sent to our servers.
Which file types work?
Excel (.xlsx) and CSV. Save older .xls files as .xlsx in Excel first. Pasting rows copied from a spreadsheet also works.
How do I reverse a 10% increase?
Divide the new price by 1.10, or enter −9.0909 as the change. 1,100 ÷ 1.10 = 1,000.
Why does the downloaded CSV use commas?
The English version writes comma-separated values with a decimal point, which English-language Excel opens directly.
Last updated: 31 October 2026 · By the Offerneta team