One tool that answers every percentage question you actually ask. The ChrysoKit Percentage Calculator has seven modes covering "X% of Y", "X is what % of Y", percent change, add/subtract a percentage, reverse a percentage and percent difference.
Why use it
Percent math is easy in principle and surprisingly easy to get wrong in practice. A mode-specific layout removes the ambiguity, pick the question, fill the two known values, read the answer.
How to use the Percentage Calculator
- Pick a mode tab: % of a number, X is what % of Y, % change, Add %, Subtract %, Reverse %, or % difference.
- Fill in the two known values.
- Read the answer with the calculation written out underneath.
- Switch modes and reuse the same numbers if needed.
Features worth knowing
Seven modes
Every common percentage question is one tab away. The labels are written in plain language so you do not need to remember the formula.
Reverse %
"After a 20% discount, the price is 80. What was the original?" Reverse mode answers this without you flipping the math by hand.
Negative changes
Percent change is direction-aware. Going from 100 to 80 is a 20% drop, not a 20% gain.
Pro tips
- For tip and tax math, the "Add %" mode is faster than computing the percentage and then adding it manually.
- Percent change is direction-aware. Going from 100 to 80 is a 20% drop, not a 20% gain.
- When two numbers feel close, run "% difference" before assuming they are interchangeable.
Privacy first. The Percentage Calculator runs entirely in your browser.
Save the Percentage Calculator. Pull it out every time the mental version starts to feel uncertain.
Open the tool: Percentage Calculator →