Percentage Calculations Explained
Percentages express a quantity as a fraction of 100 and appear in everyday financial decisions — salary hikes, GST calculations, EMI interest, investment returns, discounts, and profit margins. This calculator covers six distinct percentage calculation types so you can solve any percentage problem without remembering individual formulas.
Core Percentage Formulas
- X% of Y: Result = (X ÷ 100) × Y
- What % is A of B: Percentage = (A ÷ B) × 100
- Percentage increase/decrease: Change% = ((New − Old) ÷ Old) × 100
- Reverse percentage (find original): Original = Final × 100 ÷ (100 ± Change%)
- Discount amount: Discount = (Rate ÷ 100) × Original Price
- Sequential %: Apply percentages one after another (e.g., 10% then 5%)
Worked Examples
Example 1 — Salary hike: Your salary increases from ₹40,000 to ₹50,000. Percentage increase = ((50,000 − 40,000) ÷ 40,000) × 100 = 25%.
Example 2 — Discount: A ₹3,200 item is offered at 15% off. Discount = (15 ÷ 100) × 3,200 = ₹480. Final price = ₹3,200 − ₹480 = ₹2,720.
Example 3 — Reverse percentage: A price of ₹1,180 includes 18% GST. Original base price = 1,180 ÷ 1.18 = ₹1,000.
Note that sequential percentage changes are not additive: a 10% increase followed by a 10% decrease does not return to the original value — it gives 99% of the original (a net −1% effect). The sequential mode in this calculator handles this correctly.