Percentage Calculator

Core percent equation: $$ \text{Part} = \text{Percent (decimal)} \times \text{Whole} $$Find a percentage of a number: $$ \text{Result} = \frac{p}{100} \times N $$Find what percentage one number is of another: $$ p = \frac{\text{Part}}{\text{Whole}} \times 100 $$Find the original number from a percentage: $$ \text{Whole} = \frac{\text{Part}}{p/100} = \frac{\text{Part} \times 100}{p} $$Percentage change from one value to another: $$ \text{Percentage Change} = \frac{\text{New} – \text{Old}}{\text{Old}} \times 100 $$Increase a value by a percentage: $$ \text{New Value} = \text{Original} \times \left(1 + \frac{p}{100}\right) $$Decrease a value by a percentage: $$ \text{New Value} = \text{Original} \times \left(1 – \frac{p}{100}\right) $$Discount / percent off: $$ \text{Sale Price} = \text{Original Price} \times \left(1 – \frac{d}{100}\right) $$Tip, tax, commission, interest, fee, surcharge, or bonus added on: $$ \text{Final Total} = \text{Base Amount} \times \left(1 + \frac{r}{100}\right) $$Reverse discount: $$ \text{Original Price} = \frac{\text{Final Price}}{1 – d/100} $$Reverse increase: $$ \text{Original Value} = \frac{\text{Final Value}}{1 + r/100} $$Markup on cost: $$ \text{Selling Price} = \text{Cost} \times \left(1 + \frac{m}{100}\right) $$Target profit margin on selling price: $$ \text{Selling Price} = \frac{\text{Cost}}{1 – m/100} $$Convert decimal to percent: $$ \text{Percent} = \text{Decimal} \times 100 $$Convert percent to decimal: $$ \text{Decimal} = \frac{\text{Percent}}{100} $$Convert fraction to percent: $$ \text{Percent} = \frac{a}{b} \times 100 $$Convert percent to fraction: $$ p\% = \frac{p}{100} $$ Then simplify the fraction if possible.