Percentage calculator
Every percentage question of the day: how much is X % of Y, what share X is of Y, and the change (up or down) between two values. Twenty percent of 79 € is 15.80 €, which brings the price down to 63.20 €; a discount works the same way in reverse. A percentage is a plain number, computed on your device with nothing sent anywhere.
- 100% local
- Free · no account
- Instant result
This tool runs entirely in your browser — nothing is sent to a server.
Three questions come up constantly: what is X % of a value (a 20 % discount on €79), what share is a value of a total (45 sales out of 180), and by how many percent has a value changed (from €1,200 to €1,350). This calculator answers all three, live.
Beware the classic variation trap: a 50 % drop followed by a 50 % rise does not get you back to the starting point (100 → 50 → 75). Percentage changes are always computed relative to the starting value.
How it works
Type the figures or drop the file you want to process — the tool checks them as you go.
Everything is computed directly in your browser. Nothing is sent to a server.
The result appears instantly, with the detailed breakdown ready to copy, download or keep.
Why use this tool
No account, no download, no limit: the result appears as soon as you enter your data.
Every rule, algorithm and check reflects what we use ourselves every day at Flexina.
The calculations follow the official standards, and the step-by-step detail lets you double-check the outcome.
What does running it locally bring you?
Files, figures and documents never leave your device: nothing is stored, nothing is sent.
Once the page is loaded, you can cut the network: the tool keeps working.
No upload, no account, no third-party server in between: results stay fast and fully private.
Frequently asked questions
How do I calculate a discount?
In the “X % of Y” mode: 20 % of €79 = €15.80, i.e. a final price of €63.20. To find the pre-discount price, divide by (1 − rate): 63.20 ÷ 0.8 = €79.
How do I calculate a percentage change?
(Arrival − start) ÷ start × 100. From 1,200 to 1,350: (1350 − 1200) ÷ 1200 = +12.5 %.
What is the difference between percentage points and percent?
Going from 10 % to 12 % is a 2 percentage-point rise, but a 20 % relative increase. Both phrasings are correct — specify which one you use.