Percentage Calculator

Percentage Calculations in Everyday Life

Percentages are used everywhere — from shopping discounts and financial interest rates to statistical data and tip calculations. Mastering the four basic types of percentage calculations covered in this tool will help you make better decisions in daily life.

Real-World Examples

• What is X% of Y? — Use this when calculating tips (15% of a $50 bill), sales tax (8% of a $100 purchase), or commission (10% of $5,000 in sales).
• X is what % of Y? — Use this to find your test score (35 out of 50 is 70%), determine what portion of your budget was spent (spent $500 of a $2,000 budget = 25%), or calculate market share.
• Percentage change from X to Y — Use this for stock price changes (from $100 to $120 is a +20% change), salary increases, or population growth rates.
• Increase/Decrease by percentage — Use this to apply a discount (decrease $80 by 25% = $60), add a markup (increase cost by 30% for retail price), or calculate interest growth.

Tips for Accurate Percentage Calculations

• Remember that "percent" means "per hundred" — 25% is 25 out of 100, or 0.25 in decimal form.
• For percentage change, always divide by the original (starting) value, not the final value.
• When calculating successive percentages (e.g., applying multiple discounts), apply them sequentially rather than adding them together.
• A 100% increase means doubling. A 200% increase means tripling. A 100% decrease means going to zero.