Formulas
How to Use
Choose the type of percentage calculation you need from the three tabs.
Type your numbers into the input fields. Decimals are supported.
Click Calculate to see the instant result with a full breakdown.
Frequently Asked Questions
Multiply the number by the percentage and divide by 100. Formula: Result = (X ÷ 100) × Y. Example: 20% of 500 = (20 ÷ 100) × 500 = 100.
Divide X by Y and multiply by 100. Formula: (X ÷ Y) × 100. Example: 50 is what percent of 200? → (50 ÷ 200) × 100 = 25%.
Percentage Change = ((New Value − Old Value) ÷ Old Value) × 100. A positive result is an increase; a negative result is a decrease. Example: 80 → 100 = +25%; 100 → 80 = −20%.
Percentage is one of the most tested topics in SSC CGL, SSC CHSL, IBPS PO, SBI Clerk, CAT, and other competitive exams. Questions appear directly and also as sub-topics in Profit & Loss, SI/CI, Data Interpretation, and Ratio & Proportion.
No — this is a classic exam trap. If a number X is increased by 20%, it becomes 1.2X. Decreasing 1.2X by 20% gives 1.2X × 0.8 = 0.96X — which is 4% less than the original. The shortcut: net change = −(common%)²/100 = −(20)²/100 = −4%. This formula works for any equal successive % increase and decrease.
Let B = 100, then A = 125. B is less than A by 25 out of 125 = (25/125) × 100 = 20%. The shortcut: if A is x% more than B, then B is less than A by x/(100+x) × 100. Here: 25/125 × 100 = 20%. This "reverse percentage" type is extremely common in SSC and IBPS exams.