Calculator Use
Find a percentage or work out the percentage given numbers and percent values. Use percent formulas to figure out percentages and unknowns in equations. Add or subtract a percentage from a number or solve the equations.
How to Calculate Percentages
There are many formulas for percentage problems. You can think of the most basic as X/Y = P x 100. The formulas below are all mathematical variations of this formula.
Let's explore the three basic percentage problems. X and Y are numbers and P is the percentage:
Find P percent of X
Find what percent of X is Y
Find X if P percent of it is Y
Read on to learn more about how to figure percentages.
1. How to calculate percentage of a number. Use the percentage formula: P% * X = Y
Example: What is 10% of 150?
Convert the problem to an equation using the percentage formula: P% * X = Y
P is 10%, X is 150, so the equation is 10% * 150 = Y
Convert 10% to a decimal by removing the percent sign and dividing by 100: 10/100 = 0.10
Substitute 0.10 for 10% in the equation: 10% * 150 = Y becomes 0.10 * 150 = Y
Do the math: 0.10 * 150 = 15
Y = 15
So 10% of 150 is 15
Double check your answer with the original question: What is 10% of 150? Multiply 0.10 * 150 = 15
2. How to find what percent of X is Y. Use the percentage formula: Y/X = P%
Example: What percent of 60 is 12?
Convert the problem to an equation using the percentage formula: Y/X = P%
X is 60, Y is 12, so the equation is 12/60 = P%
Do the math: 12/60 = 0.20
Important! The result will always be in decimal form, not percentage form. You need to multiply the result by 100 to get the percentage.
Converting 0.20 to a percent: 0.20 * 100 = 20%
So 20% of 60 is 12.
Double check your answer with the original question: What percent of 60 is 12? 12/60 = 0.20, and multiplying by 100 to get percentage, 0.20 * 100 = 20%
3. How to find X if P percent of it is Y. Use the percentage formula Y/P% = X
Example: 25 is 20% of what number?
Convert the problem to an equation using the percentage formula: Y/P% = X
Y is 25, P% is 20, so the equation is 25/20% = X
Convert the percentage to a decimal by dividing by 100.
Converting 20% to a decimal: 20/100 = 0.20
Substitute 0.20 for 20% in the equation: 25/0.20 = X
Do the math: 25/0.20 = X
X = 125
So 25 is 20% of 125
Double check your answer with the original question: 25 is 20% of what number? 25/0.20 = 125
Remember: How to convert a percentage to a decimal
Remove the percentage sign and divide by 100
15.6% = 15.6/100 = 0.156
Remember: How to convert a decimal to a percentage
Multiply by 100 and add a percentage sign
0.876 = 0.876 * 100 = 87.6%
Step-by-step explanation:
