Percentage Calculator & Solver

Online calculators to solve percent problems: find percentage of a number, find whole given percent, ratio as percent, and percent change. Each shows detailed step-by-step solutions.

📐 Key Percentage Formulas
\[ \begin{aligned} &\text{1. Find B: } P\% \times A = B \quad\Rightarrow\quad B = \frac{P}{100} \times A \\[4pt] &\text{2. Find A (whole): } P\% \times A = B \quad\Rightarrow\quad A = \frac{B \times 100}{P} \\[4pt] &\text{3. Find P\% (ratio): } P\% = \frac{B}{A} \times 100\% \\[4pt] &\text{4. Percent change: } P\% = \frac{B - A}{|A|} \times 100\% \quad (A \neq 0) \end{aligned} \]

1. Find B: P% of a number A

Calculate B = (P/100) × A
Enter values
Example: 2
Example: 35
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Steps will appear here

2. Find Whole A: P% of what number equals B?

A = B / (P/100)
Enter values
Example: 2
Example: 25
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Steps will appear here

3. Find P%: B is what percent of A?

P% = (B / A) × 100%
Enter values
Example: 20
Example: 40
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Steps will appear here

4. Percent Change: From A (initial) to B (final)

P% = (B - A)/|A| × 100%
Enter values
Example: 12
Example: 24
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Steps will appear here

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