Percent Calculator
Easily calculate various ratios and percentages
Ratio Calculation (What % is A of B?)
Result
25%
25 is 100 of 25%
Calculate what percentage a number represents of a total.
Ex: If profit is $200 out of $1000 revenue → 200 ÷ 1000 × 100 = 20%
Use cases: Test score ratios, reverse discount calculation, profit margins
Percent Value (What is B% of A?)
Result
100
500 of 20% = 100
Calculate the value of a specific percentage of a total.
Ex: 20% of $3000 salary → 3000 × 0.2 = $600
Use cases: Discount amounts, tax calculation, tip calculation, savings goals
Percent Change (What % change from A to B?)
Change Rate
+25%
80 → 100 = Increase 25.00%
Calculate the percentage change between two numbers.
Ex: Stock $100 → $120 = (120-100) ÷ 100 × 100 = 20% increase
Use cases: Stock price changes, sales growth, weight changes, inflation rates
Apply Change (A with B% increase/decrease?)
Result
1,150
1,000 × (1 + 15%) = 1,150
Calculate the result of applying a percentage increase or decrease.
Ex: $1000 with 15% increase → 1000 × (1 + 0.15) = $1150
Use cases: Salary raises, discount prices, interest calculation, tax-inclusive prices
Proportion Equation (a : b = c : d)
Leave the value you want to find empty
3 : 5 = 12 : ?
Solve for the unknown in proportion a : b = c : d. (a × d = b × c)
Ex: 3 : 5 = 12 : ? → 5 × 12 ÷ 3 = 20
Use cases: Recipe scaling, map scales, currency conversion, concentration calculations