Percentage Calculator
Every percentage question in one place: what is P% of X, X is what % of Y, percent change, and increasing or decreasing a number by a percent. It calculates as you type and shows the working for your exact numbers — not a static example.
14
20% of 70
Tip: X% of Y always equals Y% of X — so 20% of 70 is the same as 70% of 20.
Every result shows its working for the exact numbers you enter. How we calculate →
How to calculate a percentage
A percentage is a fraction of 100. To find P% of a number X, multiply: (P ÷ 100) × X. So 20% of 70 is (20 ÷ 100) × 70 = 14. The calculator above shows the working for the exact numbers you type, updating as you go — no Calculate button, and no static example that ignores your figures.
Switch the mode to handle every common question: what is P% of X, X is what % of Y, the percent change between two numbers, or increasing and decreasing a value by a percentage.
What percentage is one number of another?
To find what percent X is of Y, divide and multiply by 100: (X ÷ Y) × 100. For example, 15 out of 50 is (15 ÷ 50) × 100 = 30%. This is the calculation behind test scores, completion rates and 'how much of my goal have I reached'. Pick the X is what % of Y mode above and the steps appear with your numbers.
Percentage increase and decrease
To increase a value by a percent, multiply by one plus the percent: X × (1 + P ÷ 100). A $40 item with a 25% markup becomes $50. To decrease — a discount or markdown — multiply by one minus the percent: a $40 item at 25% off is $30. The increase and decrease modes above handle prices, raises, tips and discounts in one step.
Percent change between two numbers
Percent change measures how much a value grew or shrank: ((new − old) ÷ |old|) × 100. Going from 80 to 100 is a 25% increase; going from 100 to 80 is a 20% decrease — note they aren't the same percentage, because the starting point is different. Use the % change mode above for prices, populations, metrics and before/after comparisons.
A useful shortcut: X% of Y = Y% of X
Percentages are commutative, so X% of Y always equals Y% of X. That sounds abstract until you use it: 4% of 75 is awkward, but 75% of 4 is obviously 3 — same answer, far easier. Whenever one order looks hard, flip it. The calculator points this out for you in the P% of X mode.
Percentages in everyday life
Most day-to-day math is percentages: a 20% tip on a $60 meal ($12), a 30%-off sale, sales tax, a 3% raise, exam scores, or interest on savings. The same five operations above cover all of them — and because every result shows its working, the calculator doubles as a quick way to learn or double-check the method, not just get an answer.
Frequently asked questions
How do I calculate a percentage?
To find P% of a number, multiply the number by P ÷ 100. For 20% of 150, that's 150 × 0.20 = 30. To find what percent one number is of another, divide them and multiply by 100. The calculator above does both and shows the steps for your exact numbers.
What is 20% out of 70?
20% of 70 is (20 ÷ 100) × 70 = 14. A quick check using the flip rule: 20% of 70 equals 70% of 20, and 70% of 20 is also 14.
What is 30% out of 300?
30% of 300 is (30 ÷ 100) × 300 = 90. Enter 30 and 300 in the 'What is P% of X' mode above to see the working.
How do I calculate 15% of 50?
15% of 50 is (15 ÷ 100) × 50 = 7.5. Using the shortcut, that's the same as 50% of 15, which is also 7.5 — sometimes the flipped version is easier to do in your head.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100: X is (X ÷ Y) × 100 percent of Y. For instance, 18 out of 24 is (18 ÷ 24) × 100 = 75%. Use the 'X is what % of Y' mode above.
How do I calculate percentage increase or decrease?
For an increase, multiply by (1 + percent ÷ 100); for a decrease, multiply by (1 − percent ÷ 100). A $200 price raised 10% is $220; cut 10% it's $180. The increase and decrease modes above handle markups, discounts, tips and raises.
How do I calculate percent change between two numbers?
Subtract the old value from the new, divide by the old value, and multiply by 100: ((new − old) ÷ |old|) × 100. From 50 to 65 is a 30% increase. Note an increase and the reverse decrease aren't equal percentages, because the base changes.
Is X% of Y the same as Y% of X?
Yes — percentages are commutative, so X% of Y always equals Y% of X. For example, 8% of 50 equals 50% of 8, which is 4. It's a handy trick when one order is easier to compute than the other.
Researched & verified by the Calcuris Data & Research Team. How we build and check our tools →