Percentage Calculator
Solve any percentage question instantly — from "What is 15% of 200?" to percentage change and reverse calculations. Results update as you type.
All five calculators below update instantly as you type — no button needed. Pre-filled with example values so you can see results right away.
What are you calculating?
What is X% of Y?
Result = (X ÷ 100) × Y
Result
30
What are you calculating?
X is what percent of Y?
Result = (X ÷ Y) × 100
Percentage
15%
What are you calculating?
Percentage change from X to Y
Change = ((Y − X) ÷ |X|) × 100
% Increase
+25%
What are you calculating?
X increased or decreased by Y%
New Value = X × (1 + Y ÷ 100)
New Value
300
What are you calculating?
X is Y% more/less than Z — find Z
Z = X ÷ (1 + Y ÷ 100)
Base Value (Z)
100
Quick Reference — Percentage Formulas
X% of Y
(X ÷ 100) × Y
X as % of Y
(X ÷ Y) × 100
% change
((new − old) ÷ |old|) × 100
After increase
X × (1 + Y ÷ 100)
After decrease
X × (1 − Y ÷ 100)
Find base value
X ÷ (1 ± Y ÷ 100)
Frequently Asked Questions
- Is the Percentage Calculator free?
- Yes, 100% free. No account, no limits, and no ads blocking the result.
- How do I calculate what percent X is of Y?
- Divide X by Y, then multiply by 100. For example, 30 is what percent of 200? → (30 ÷ 200) × 100 = 15%. Use the second calculator card on this page for instant results.
- What is the formula for percentage change?
- Percentage change = ((New Value − Old Value) ÷ |Old Value|) × 100. A positive result means an increase; a negative result means a decrease.
- How do I find the original value before a percentage increase?
- If a value X is Y% more than the original Z, then Z = X ÷ (1 + Y/100). For example, 120 is 20% more than 120 ÷ 1.20 = 100. Use the last calculator card on this page.
- What is the difference between percentage increase and percentage change?
- They are the same formula. 'Percentage increase' is used when the result is positive (value went up). 'Percentage change' covers both increases and decreases — a negative result simply means a decrease.
- Does it work on mobile?
- Yes, the calculator works on all modern browsers including mobile Safari and Chrome on iOS and Android.