To calculate a percentage of a number, convert the percentage to a decimal (by dividing by 100), then multiply by the number. For example, to find 25% of 200: Convert 25% to 0.25, then multiply: 0.25 × 200 = 50. Alternatively, you can use the formula: (Percentage ÷ 100) × Number. Our calculator does this instantly—just enter the percentage and the number!

Percentage increase compares a new value to an original value and shows the growth relative to that starting point. Formula: [(New - Original) ÷ Original] × 100. Percentage difference compares two values symmetrically, showing how different they are relative to their average. Formula: [|Value1 - Value2| ÷ ((Value1 + Value2) ÷ 2)] × 100. Use percentage increase when one value is clearly the starting point (like salary changes). Use percentage difference when comparing two values with no clear baseline (like comparing prices between two stores).

Reverse percentages help you find the original value when you know the final amount and the percentage change. For example, if something costs $120 after a 20% increase, you can find the original price by dividing the final value by (1 + percentage/100). So: $120 ÷ 1.20 = $100. For decreases, use (1 - percentage/100) instead. This is super useful for figuring out pre-sale prices, original salaries before raises, or any situation where you need to work backwards from a percentage change. Our reverse percentage calculator handles this automatically!

Absolutely! Percentages over 100% are completely valid and common. They indicate that something is more than the whole or has more than doubled. For example, if sales increase from 50 to 150 units, that's a 200% increase (it tripled!). You might see 150% effort (giving more than expected), 300% growth (quadrupling), or score 120% on a test with bonus questions. Percentages over 100% just mean you're dealing with values greater than the original reference point. There's no upper limit to percentages!

This is one of the trickiest things about percentages! Here's why: percentages are always calculated based on the current value, not the original. Example: Start with $100. A 50% increase gives you $150 ($100 + $50). Now a 50% decrease is calculated on $150, not $100. So you lose $75 (50% of $150), ending at $75. You've actually lost 25% overall! The same principle applies in reverse: a 50% decrease followed by a 50% increase also doesn't return to the original. This is why understanding the base value is crucial in percentage calculations. It's not intuitive, but it's how percentages work!

Converting fractions to percentages is easy! Simply divide the numerator (top number) by the denominator (bottom number), then multiply by 100. For example, to convert 3/4 to a percentage: 3 ÷ 4 = 0.75, then 0.75 × 100 = 75%. Some common conversions to remember: 1/2 = 50%, 1/4 = 25%, 3/4 = 75%, 1/5 = 20%, 1/10 = 10%. For quick mental math, if the denominator is a factor of 100 (like 2, 4, 5, 10, 20, 25, 50), you can multiply both numerator and denominator to get a denominator of 100, then the numerator is your percentage!

Here's a pro tip for restaurants! First, find 10% by moving the decimal point one place left ($50.00 becomes $5.00). For 20% tip, double the 10% amount ($5 × 2 = $10). For 15%, add 10% plus half of 10% ($5 + $2.50 = $7.50). For 18%, find 20% and subtract a little. For tax around 8%, use 10% minus 2%. Example: $50 bill with 8% tax and 20% tip: Tax = $5 - $1 = $4, Tip = $10, Total = $64. Or just use our calculator! It's faster and perfect when you're hangry or doing quick mental math after a few drinks!

Calculating percentage change with negative numbers can be tricky! If you're going from a negative to a positive (or vice versa), the percentage change can be very large or even undefined. For example, going from -$100 loss to +$50 profit isn't just a 150% change—it's a complete reversal! The standard formula [(New - Original) ÷ Original] × 100 still works mathematically, but the interpretation becomes complex. When dealing with negative numbers, it's often clearer to describe the absolute change in dollars or units rather than percentages. If you must use percentages with negatives, be very careful about interpretation and consider using absolute values or alternative metrics.

This is a super common confusion! Percentage points measure the arithmetic difference between two percentages, while percent measures the relative change. Example: If interest rates go from 5% to 8%, that's a 3 percentage point increase (8 - 5 = 3), but it's a 60% relative increase [(8-5)÷5 × 100 = 60%]. When describing changes in things already expressed as percentages (like interest rates, unemployment, test scores), use percentage points for the absolute difference. Use percent for relative changes. Mixing these up can make differences seem much larger or smaller than they really are! Media often gets this wrong, so stay sharp!

Yes! Our percentage calculator (and most digital calculators) handle large numbers with extreme precision. Modern computers use floating-point arithmetic that can accurately process numbers with many decimal places. Whether you're calculating percentages for $10 or $10,000,000, the mathematical operations remain the same and equally accurate. The only potential issue is rounding—if you need results to a specific decimal place for financial reporting, make sure to round appropriately. Our calculator displays results with high precision, so you can round to whatever level of accuracy your situation requires. For most real-world applications, our calculator is more accurate than manual calculations!