Percentage Calculator
Calculate percentages easily - find what percent one number is of another, calculate percentage of a number, or determine percentage increase and decrease.
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How to Use This Calculator
Percentages come up everywhere - discounts, tips, grades, statistics. Our calculator handles all the common percentage calculations:
- Choose your calculation type from the options provided.
- For 'What is X% of Y': Enter the percentage and the number to calculate the portion (e.g., What is 15% of 200?).
- For 'X is what % of Y': Enter both numbers to find the percentage relationship (e.g., 30 is what % of 150?).
- For percentage increase/decrease: Enter the original and new values to find the percent change.
- Click 'Calculate' to see your result instantly.
Why This Matters
Percentages are fundamental to everyday decision-making, from understanding sale prices to analyzing data at work. Whether you're calculating a discount, figuring out a tip, determining grade scores, or analyzing business metrics, percentage calculations help you make sense of proportions and changes. A solid grasp of percentages helps you spot deals, understand statistics in the news, and make better financial decisions.
- Quickly verify discounts and sale prices while shopping
- Calculate grades and scores for school or work assessments
- Understand statistical data and research findings
- Compare proportional changes across different scenarios
- Make informed financial decisions about raises, investments, and expenses
Worked Examples
Sale Discount
A $80 shirt is 25% off. What's the discount amount and final price?
Grade Calculation
You scored 42 out of 50 on a test. What's your percentage?
Salary Increase
Your salary went from $52,000 to $56,000. What percent raise is that?
Common Mistakes to Avoid
- Confusing percentage points with percent - a rate going from 5% to 7% is a 2 percentage point increase but a 40% relative increase.
- Forgetting that percentage increase and decrease aren't reversible - a 50% increase followed by 50% decrease doesn't return to the original.
- Calculating percent change using the new value instead of the original - always divide by the starting value.
- Mixing up 'of' and 'off' - 20% of $100 is $20, but 20% off $100 means you pay $80.
- Not converting percentages to decimals for calculations - 15% = 0.15 when multiplying.