What is X% of Y?
Find a percentage of any number — e.g. "What is 18% of 5000?"
%
Result
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Enter values above to see the result
Common Percentage Shortcuts
50% of X
Divide X by 2
25% of X
Divide X by 4
10% of X
Divide X by 10
1% of X
Divide X by 100
18% GST
× 1.18 to add GST
% Discount
× (1 − d/100)
Percentage Formulas — Quick Reference
X% of Y
Result = Y × X ÷ 100
e.g. 18% of 5000 = 5000 × 18 ÷ 100 = 900
X is what % of Y?
Result = (X ÷ Y) × 100
e.g. 900 of 5000 = (900÷5000)×100 = 18%
% Change
((New−Old) ÷ Old) × 100
e.g. 50K→65K = ((65−50)÷50)×100 = 30%
Value after %
New = Old × (1 ± p/100)
e.g. 1000 + 10% = 1000 × 1.1 = 1100
Frequently Asked Questions
Common percentage calculation questions
How do I calculate a percentage of a number?
To find X% of Y: multiply Y by X, then divide by 100. Formula: Y × X ÷ 100. Example: 20% of 500 = 500 × 20 ÷ 100 = 100. Shortcut: for 10%, move the decimal one place left (10% of 500 = 50).
How do I calculate percentage change?
% Change = ((New Value − Old Value) ÷ Old Value) × 100. If the result is positive, it's an increase. If negative, it's a decrease. Example: salary goes from ₹50,000 to ₹60,000 → ((60,000−50,000)÷50,000)×100 = 20% increase.
How do I find the original price before a discount?
To find the original price before a X% discount: Original = Sale Price ÷ (1 − X/100). Example: item costs ₹800 after 20% discount → Original = 800 ÷ 0.80 = ₹1,000. This is "reverse percentage" or "back-calculation."
How is GST calculated as a percentage?
To add 18% GST: Price with GST = Base Price × 1.18. To remove 18% GST from an inclusive price: Base Price = GST-inclusive Price ÷ 1.18. Use the "Value after %" mode above to quickly add or remove any GST rate.