How it works
The "Percentage Calculator" is designed for quick percentage problem-solving. Simply choose the appropriate formula, enter 2 values, and click "Calculate" to see the result.
You can copy the result after the calculation by pressing the button in the answer field.
For instance, if you want to find out what 20% of 150 is, enter the values 20 and 150 into the first formula and press "Calculate". The answer, 30, will appear in the field to the right of the button.
Below, you can explore the different calculator options and the formulas they use. Each description provides a detailed example with a solution.
What is n percent of a?
x = a ÷ 100 × n
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a - initial number
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n - percentage amount
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x - final number
Task: An adult human body is composed of 70% water. What is the weight of the water in a person who weighs 76 kg?
Solution: Initial number (a) is 76, percentage (n) is 70. We are looking for x.
1) First, find 1 percent: 76 ÷ 100 = 0.76
2) Now, find 70 percent: 0.76 × 70 = 53.2
Answer: 53.2 kg
You can calculate it this way or use our calculator for a quick and accurate result.
What percentage is a of b?
x = a ÷ b × 100
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a - part of the whole
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b - initial number
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x - percentage amount
Task: The factory's annual plan is to produce $16,250 worth of products. In the first quarter, it produced $5,850 worth of products. What percentage of the annual plan is that?
Solution: Here, a is 5,850 and b is 16,250. We need to find x.
1) Determine the ratio: 5,850 ÷ 16,250 = 0.36
2) Convert to a percentage: 0.36 × 100 = 36
Answer: 36%
This formula is handy for quickly finding what fraction one number is of another. You can also do this instantly with our calculator.
If a is n percent, what is the total?
x = a ÷ n × 100
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a - initial number
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n - percentage amount
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x - desired number
Task: A school team scored 72 points in a competition. These points are 80% of the total possible. What is the total number of points available?
Solution: a is 72, n is 80, and we are looking for x.
1) First, find 1%: 72 ÷ 80 = 0.9
2) Then find 100%: 0.9 × 100 = 90
Answer: 90 points
Use this formula or simply input the values into our calculator.
By what percentage did a increase to become b?
x = (b - a) ÷ a × 100
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a - smaller number
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b - larger number
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x - percentage amount
Task: An item cost $40, and then its price was increased to $44. By what percentage did the price increase?
Solution: If a = 40 and b = 44, find x.
1) The difference: 44 - 40 = 4
2) Ratio of the difference to the original: 4 ÷ 40 = 0.1
3) Convert to percent: 0.1 × 100 = 10
Answer: 10%
If the result is negative, it means the number was decreased, not increased.
By what percentage did a decrease to become b?
x = (a - b) ÷ a × 100
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a - larger number
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b - smaller number
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x - percentage amount
Task: An iron cost $50. After some time, its price dropped to $44. By what percentage was the price reduced?
Solution: If a = 50 and b = 44, find x.
1) Difference: 50 - 44 = 6
2) Ratio: 6 ÷ 50 = 0.12
3) Convert to percentage: 0.12 × 100 = 12
Answer: 12%
If the result is negative, it means the number has increased instead of decreased.
Increase a by n percent.
x = a × (100 + n) ÷ 100
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a - initial number
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n - percentage
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x - final number
Task: Last year, a store bought 200 Christmas trees. This year, that number increased by 120%. How many trees were purchased this year?
Solution: a = 200, n = 120, we need x.
1) Total percentage relative to last year: 100 + 120 = 220
2) Convert to a multiplier: 220 ÷ 100 = 2.2
3) Multiply last year's number by that multiplier: 200 × 2.2 = 440
Answer: 440 trees
Alternatively, add 1.2 (120% as a fraction) to 1, then multiply: (1 + 1.2) × 200 = 440.
Decrease a by n percent.
x = a × (100 - n) ÷ 100
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a - initial number
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n - percentage
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x - desired number
Task: Apples lose 84% of their weight when dried. How many kilograms of dried apples can be obtained from 300 kg of fresh apples?
Solution: a = 300, n = 84, find x.
1) Remaining percentage: 100 - 84 = 16
2) Convert to a fraction: 16 ÷ 100 = 0.16
3) Multiply the original weight: 300 × 0.16 = 48
Answer: 48 kg
Similarly, you could do (1 - 0.84) × 300 = 48.
That's it! Now you see these tasks aren't as complicated as they seem, and you can handle them quickly and easily. Tell your friends about Percentage Calculator—it may be useful for them too.