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Percentage Calculator

Calculate percentages, percentage change and increases or decreases, with the formula and steps shown.

SIMILAR CALCULATOR

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Unit Converter

Convert between units across 12 categories, including length, weight, temperature, area and volume.

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Scientific Calculator

An online scientific calculator with trigonometry, logarithms, exponents and factorials.

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Fraction Calculator

Add, subtract, multiply, divide and simplify fractions, with mixed-number and decimal output.

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WHAT IS PERCENTAGE CALCULATOR?

Percentage Calculator offers five distinct, unambiguous modes rather than one confusing generic form: "X% of Y", "X is what % of Y", "X is Y% of what", "percentage change", and "increase/decrease by %" — each shows the formula and the substituted calculation steps.

Features

  1. Every mode calculates instantly and shows the formula plus substituted steps — never just a bare number.
  2. Division by zero (e.g. a zero total, or percentage change from a zero base) shows a clear error — never a displayed Infinity or NaN.
  3. Accepts decimals and negative numbers; results strip meaningless trailing zeroes.

How to use?

  1. Choose one of the five calculation modes above.
  2. Enter your values — the result, formula, and steps update instantly.
  3. Click “Copy result” or “Reset”.

Frequently asked questions

Why does the result never show Infinity or NaN?

When a total or percent is 0 and would cause division by zero, the tool shows a clear error message (e.g. "Total cannot be 0") instead of a meaningless Infinity or NaN.

What is the difference between "percentage change" and "increase/decrease by %"?

"Percentage change" works backward from an old and new value to find how much it changed; "increase/decrease by %" works forward from a value and a percent to find the adjusted result — they go in opposite directions.

Can I enter negative numbers?

Yes — every mode accepts negative numbers and decimals, and the formula and steps reflect exactly what you entered.

12

Formula: X% of Y = (X / 100) × Y

Steps: (20 / 100) × 60 = 12