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Calculator Tools Browser-Only / 100% Private

Percentage Calculator

Solve three essential percentage problems: X% of Y, X is what % of Y, and percentage increase or decrease.

Calculated Result: 30 (20 / 100) × 150 = 30

What is the Percentage Calculator?

The Membuat Percentage Calculator solves the three most common mathematical percentage questions encountered in finance, sales discounting, tip calculations, corporate reporting, and academic study. It provides immediate results accompanied by clear, step-by-step arithmetic formulas so you can understand the exact underlying math.

How to Use This Tool

  1. Select your calculation mode using the tabs: "What is P% of X?", "X is what % of Y?", or "% Increase or Decrease".
  2. Enter your numbers into the respective input fields.
  3. View the calculated result and formula explanation updated instantaneously.
  4. Click "Copy Result" to save the number, or "Reset Values" to start over.

Examples & Use Cases

Retail Discount (What is P% of X?)

Input: What is 15% discount on $120 shoes?
Result: $18.00 savings (Formula: (15 / 100) * 120 = 18)

Exam Score (X is what % of Y?)

Input: Score of 42 correct answers out of 50 total questions
Result: 84.00% (Formula: (42 / 50) * 100 = 84%)

Year-over-Year Growth (% Increase/Decrease)

Input: Revenue grew from $50,000 to $85,000
Result: +70.00% Increase (Formula: ((85000 - 50000) / 50000) * 100 = +70%)

Formula & Technical Specifications

Mode A: P% of X = (P / 100) * X. Mode B: X of Y = (X / Y) * 100. Mode C: Percentage Change = ((New - Old) / |Old|) * 100.

Limitations, Edge Cases & Best Practices

In Mode B and Mode C, the denominator cannot equal zero, as division by zero is mathematically undefined.

Privacy & Client-Side Execution

Calculations run purely in JavaScript. No numbers leave your device.

Frequently Asked Questions

What is the formula for percentage increase?

Subtract the original value from the new value, divide by the absolute original value, and multiply the quotient by 100.

Can percentages be greater than 100%?

Yes. If a value more than doubles, the increase is greater than 100%. For example, an increase from 10 to 30 represents a 200% increase.