Percentage Calculator — All 8 Formulas with Steps

Mode
X% of Y = (X / 100) × Y
Calculate X% of Y with step-by-step solution
Percentage change from A to B
Find the original price before the discount
Full breakdown: discount, tax, and total
Use +X% or -X% for percentage steps; +X or -X for absolute amounts
Examples
%

Enter values to calculate

Pick a mode above and the result updates as you type. Try one of the examples to see a worked solution.

Python template
% of X% of Y = (X / 100) × Y
% change ((B − A) / A) × 100%
Reverse Original = Final / (1 − Disc% / 100)
Powers
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Frequently asked

To find X% of Y, multiply Y by X / 100. For example, 25% of 200 = (25 / 100) × 200 = 0.25 × 200 = 50. The formula is Result = (X / 100) × Y.
Percent change = ((B − A) / A) × 100. For example, going from 120 to 150 gives ((150 − 120) / 120) × 100 = +25% increase. A negative result means a decrease.
Divide the final price by 1 − (Discount% / 100). If the final price is $75 after a 25% discount, the original is $75 / 0.75 = $100. Formula: Original = Final / (1 − Disc% / 100).
Each step applies to the running total, not the original. Starting at 100: +10% gives 110, then −10% gives 99 (not 100). The second step uses 110 as its base, so +X% followed by −X% never returns to the start.
Yes — 100% free with no signup. You get 8 calculation modes with step-by-step KaTeX solutions, a discount + tax simulator, chained steps, a Python compiler, LaTeX export, and shareable URLs. All computation runs in your browser.