Use this Percentage Calculator to quickly compute percent values, find what percent one number is of another, or calculate percentage increase or decrease. Fast, accurate, and ideal for finance, discounts, or data analysis.
The Percentage Calculator solves the two most common percentage problems: finding what percent one number is of another, and calculating a specific percentage of a given number. It's used every day for discounts, tips, grades, taxes, markups, and financial analysis.
Percentage of a number: Part = (Percentage ÷ 100) × Base What percent of base: Percentage = (Part ÷ Base) × 100
1. Sales tax on a purchase. You buy a $48 jacket in a state with 7.5% sales tax. Find the tax, then the total:
Tax = (7.5 ÷ 100) × 48 = $3.60 Total = 48 + 3.60 = $51.60
2. Test score as a percentage. You answered 34 questions correctly on a 40-question exam. Convert the score to a percentage:
Score = (34 ÷ 40) × 100 = 85%
3. Sales commission. A real-estate agent earns a 3% commission on a $245,000 home sale:
Commission = (3 ÷ 100) × 245,000 = $7,350
This table shows how the same percentages apply to a few common base numbers — handy for fast mental estimates:
| Percent | of 50 | of 100 | of 250 | of 1,000 |
|---|---|---|---|---|
| 1% | 0.5 | 1 | 2.5 | 10 |
| 5% | 2.5 | 5 | 12.5 | 50 |
| 10% | 5 | 10 | 25 | 100 |
| 20% | 10 | 20 | 50 | 200 |
| 25% | 12.5 | 25 | 62.5 | 250 |
| 50% | 25 | 50 | 125 | 500 |
| 75% | 37.5 | 75 | 187.5 | 750 |
A percentage is just a fraction out of 100, so the three forms are interchangeable:
Percent → Decimal: divide by 100 → 45% = 0.45 Decimal → Percent: multiply by 100 → 0.6 = 60% Percent → Fraction: write over 100 → 25% = 25/100 = 1/4
Knowing the common equivalents speeds up mental math: 25% = ¼, 50% = ½, 75% = ¾, 10% = 1/10, and 33⅓% = 1/3.
To add a percentage, multiply by (1 + rate); to subtract one, multiply by (1 − rate):
Add 8% tax to $50: 50 × 1.08 = $54.00 Take 25% off $60: 60 × 0.75 = $45.00
This one-step method avoids calculating the percentage separately and then adding or subtracting it.
A common source of confusion: if an interest rate rises from 3% to 5%, it increased by 2 percentage points (an absolute change) — but the relative percentage increase is (5 − 3) ÷ 3 × 100 = 66.7%. Percentage points describe a change in a rate itself; percent change describes how large that change is relative to the starting value. For tracking change between two values over time, use the Percentage Change Calculator.
If you know the price after a discount but need the original, divide by (1 − discount rate):
Original = Sale Price ÷ (1 − Discount Rate) Example: $80 after 20% off → $80 ÷ 0.80 = $100 original price
For a markup: divide by (1 + markup rate). Example: $130 after a 30% markup → $130 ÷ 1.30 = $100 cost. To compare two values symmetrically, see the Difference Calculator.
Multiply the base by the percentage, then divide by 100. Formula: Part = (Percentage ÷ 100) × Base. Example: 25% of 200 = (25 ÷ 100) × 200 = 50.
Divide the part by the base, then multiply by 100. Formula: Percentage = (Part ÷ Base) × 100. Example: 50 is what percent of 200? → (50 ÷ 200) × 100 = 25%.
Multiply the bill by the tip percentage divided by 100. For a 20% tip on a $75 bill: (20 ÷ 100) × 75 = $15. Use the 'Find a Percentage of a Number' section above.
Percentage points measure an absolute difference between two percentages. If an interest rate rises from 3% to 5%, that's 2 percentage points — but a 66.7% relative increase. Percentage change measures the relative shift.
Divide the discounted price by (1 − discount rate). Example: an item costs $80 after a 20% discount. Original price = $80 ÷ 0.80 = $100. This is called a reverse percentage.
100% of any number equals the number itself. 200% is double the value; 50% is half. For example, 150% of 60 = 90.
Yes. It supports decimal percentages (e.g., 7.5%) and negative values for all operations.
Percentages appear in finance (interest rates, investment returns), retail (discounts, markups, tax), education (grades, test scores), nutrition labels, statistics, and everyday tasks like tipping or splitting bills.
Multiply the number by 1 plus the rate as a decimal. To add 8% sales tax to a $50 subtotal: 50 × 1.08 = $54. The shortcut works because adding 8% is the same as keeping 100% and adding 8%, which equals 108% (1.08) of the original.
Multiply the number by 1 minus the rate as a decimal. To take 25% off a $60 item: 60 × (1 − 0.25) = 60 × 0.75 = $45. You can also find the 25% portion ($15) and subtract it from $60 — both methods give the same answer.
To convert a percentage to a decimal, divide by 100 (move the decimal point two places left): 45% = 0.45. To convert to a fraction, write the percentage over 100 and simplify: 45% = 45/100 = 9/20. To go back to a percentage, multiply a decimal by 100 or convert the fraction to a decimal first.
No — percentage changes do not add directly because each applies to a different base. A 10% increase followed by a 10% decrease does not return you to the start: 100 → 110 → 99, a net 1% loss. To combine them, multiply the factors: 1.10 × 0.90 = 0.99.
Use 10% as an anchor: 10% of any number is that number with the decimal moved one place left (10% of 80 is 8). From there, 5% is half of 10%, 20% is double, and 1% is the decimal moved two places. To find 15% of 80: 10% is 8, 5% is 4, so 15% is 12.