Find a percentage of a number
| Cell | Meaning | Example value |
|---|---|---|
| A2 | Percentage | 20% |
| B2 | Number | 150 |
Formula
=A2*B2Expected result: 30
Enter A2 as 20% or 0.20. Entering 20 without the percent sign multiplies by 20.
Percentage Calculator
Calculate a percentage of a number, or switch modes to find what percentage one number is of another.
Calculate Percentage
%
ofHow it works
Formula and steps
The formula shows how the percentage calculator turns your inputs into the result. Use it to check the calculation, then follow the example steps to see each part of the math.
Formula & steps
Percent of a number formula
R = (p / 100) x V
Use this when you want to find a percentage of a value.
R= Result, or calculated amountp= Percentage you want to calculateV= Value the percentage is applied toWhat percentage one number is of another
p = (A / W) x 100
Use this when you know the part and whole and want to find the percentage.
p= Calculated percentageA= Part, or amount being comparedW= Whole, or reference total; cannot be zero- 1Convert the percentage to a decimal: 20 / 100 = 0.2.
- 2Multiply that decimal by the value: 0.2 x 150 = 30.
- 3So, 20% of 150 equals 30.
Worked examples
Example 1
What is 20% of 150?
- 1
Convert the percent to a decimal
20 / 100 = 0.20
- 2
Multiply by the number
0.20 x 150 = 30
- 3
Answer
20% of 150 is 30
Example 2
30 is what percent of 150?
- 1
Divide the part by the whole
30 / 150 = 0.20
- 2
Convert the decimal to a percent
0.20 x 100 = 20%
- 3
Answer
30 is 20% of 150
Spreadsheet formulas
Calculate in Excel or Google Sheets
Enter the example values in the listed cells, then paste the formula into another cell. Excel and Google Sheets use the same formulas shown here.
Find what percentage one number is of another
| Cell | Meaning | Example value |
|---|---|---|
| A2 | Part | 30 |
| B2 | Whole | 150 |
Formula
=A2/B2Expected result: 20%
Format the result cell as a percentage. The whole in B2 cannot be zero.
Common uses
- Finding a tip, tax, fee, or discount amount
- Calculating part of a budget, score, or total
- Finding what percent one number is of another
- Turning a percentage rate into an actual number
Common mistakes
- Multiplying by 20 instead of 0.20. A percentage must be divided by 100 before multiplying.
- Reversing the part and whole when finding a percentage. Divide the part by the whole, not the whole by the part.
- Confusing the percentage with the calculated amount. In 20% of 150, 20% is the rate and 30 is the amount.
Percentage guide
How to calculate percentages
First identify which number is the percentage, which is the part, and which is the whole. The operation depends on the unknown value.
Find a percentage of a number
Convert the percentage to a decimal by dividing by 100, then multiply by the number. For 20% of 150, calculate 0.20 x 150 to get 30.
Calculate a sale price and savings →Find what percent one number is of another
Divide the part by the whole, then multiply by 100. If 30 is the part and 150 is the whole, 30 / 150 x 100 = 20%. The whole cannot be zero.
Calculate a percentage of a percentage →Choose old-to-new calculation for growth or decline
When one value is explicitly the starting point and another is the result, use percentage change instead of a general part-of-whole calculation.
Calculate percentage change →FAQ
Divide the percent by 100, then multiply by the number. For example, 20% of 150 is 0.20 x 150 = 30.
Divide the part by the whole, then multiply by 100. If 30 is the part and 120 is the whole, the answer is 25%.
Multiply the decimal by 100 and add the percent sign. For example, 0.375 x 100 = 37.5%.
Yes. A percentage above 100% represents more than the full reference amount. For example, 150% of 40 is 60.
More Percentage calculators
Browse other categories