Percentage Calculator

Find %, Increase, Decrease, Reverse, Add & Subtract Percent

Solve Any Percentage Problem

AI often makes mistakes with percentages. Get precise results instantly with step-by-step formulas.

What is X% of Y?

% of
10% of 500 15% of 80 25% of 1200 50% of 1000 8% of 250
Enter numbers to calculate

X is what % of Y?

is what % of
40 is what % of 200 75 is what % of 300 12 is what % of 48 90 is what % of 120
Enter numbers to calculate

From X to Y — what is the % change?

→
100 → 150 200 → 150 50 → 65 80 → 40
Enter numbers to calculate

X is Y% of what number?

is % of ?
30 is 20% of ? 75 is 60% of ? 50 is 12.5% of ?
Enter numbers to calculate

X ± Y% = ?

%
Quick presets: 100 + 10% 200 + 15% 150 - 20% 500 - 25%
Enter numbers to calculate

Why Use This Percentage Calculator?

🧮 Five Calculators in One

Percent of a number, what percent, percentage change, reverse percentage, and add/subtract — all in one tool.

⚡ Instant Results

Results update as you type. No submit button needed. See the answer, formula, and step-by-step breakdown instantly.

🔢 AI-Proof Accuracy

AI models frequently miscalculate percentages in complex scenarios. This tool uses precise mathematical formulas every time.

💼 Real-World Scenarios

Tips, discounts, tax, investment returns, grade calculations, salary changes, and more.

🔒 100% Private

All calculations happen in your browser. No data is sent to any server. No signup required.

📱 Works Everywhere

Desktop, tablet, or mobile. Responsive design, no app download needed.

Common Use Cases

  • Shopping: Calculate sale discounts ("30% off $80")
  • Dining: Figure out tip amounts ("15% tip on $45")
  • Finance: Compute investment returns, tax rates, and interest changes
  • Academic: Calculate exam scores, grade percentages, and GPA
  • Business: Analyze growth rates, market share, and profit margins
  • Health: Track weight change percentages and body composition

How to Use

  1. Select a calculation mode from the tabs above
  2. Enter your numbers in the input fields
  3. Results update instantly — including the formula and step-by-step explanation
  4. Click example buttons to try common scenarios

Frequently Asked Questions

How do I calculate a percentage of a number?

Use the "% of Number" mode. For example, to find 20% of 200: 20 ÷ 100 × 200 = 40.

How do I find the percentage increase?

Use the "% Change" mode. Enter the original value as "From" and the new value as "To". The calculator shows both the percentage change and whether it's an increase or decrease.

How do I reverse a percentage?

Use the "Reverse %" mode. If you know that 40 is 25% of some number, enter 40 and 25% to find the original number: 40 ÷ 25 × 100 = 160.

Is this calculator accurate?

Yes, all calculations use standard mathematical formulas with up to 4 decimal places of precision. Results are verified against industry-standard formulas.

Is it really free?

Yes, completely free with no signup, no ads, and no usage limits. All calculations run locally in your browser.