The Calculator
04 ModesResult
LiveThe Four Modes
How it worksEvery percentage question is one of these four.
A slice of a whole
You know the total and the rate. You want the amount. Tips, fees and VAT are all this shape.
50,000 × 0.15 = 7,500
How big is the part
You hold two amounts and want the rate between them. Completion rates and market share live here.
20 ÷ 80 × 100 = 25%
How much it moved
Measured against where it started. Careful — going back down is not the same rate, because the base moved.
100 → 130 = +30% · 130 → 100 = −23%
What you actually pay
Stacked discounts multiply, they never add. Twenty then ten is not thirty off.
0.8 × 0.9 = 0.72 → 28% off
Questions
03Do my numbers get sent anywhere?
No. Everything is computed inside your browser and nothing is stored.
Percent versus percentage point?
A rate going from 3% to 5% is a 2 point rise and a 66.7 percent rise. Points measure the gap; percent measures the change in the ratio itself.
Does it work on mobile?
Yes. No install, no login — it opens in the browser.