Percent

Pronunciation: /pərˈsɛnt/ Explain

Percent is a ratio meaning for every 100 parts. The symbol for percent is '%'. 50% means 50 parts out of 100 parts, or 50 / 100 = 0.5.

How to convert a ratio to a percentage

To convert a ratio to percentage, divide the numerator by the denominator, then multiply by 100 and add the percent sign.

Example 1: There are 20 students in a classroom. 9 of the students are girls. What percentage of the students are girls?

Step	Description	Calculation
1	Find the ratio. Since 9 out of 20 students are girls, the ratio is 9 / 20.	9 / 20
2	Divide the ratio.	9 / 20 = 0.45
3	Multiply by 100.	0.45 · 100 = 45
4	Add the percent sign.	45%
Table 1: Convert a ratio to a percentage example 1

Example 2: There are 250 students in a school. 100 students prefer strawberry ice cream over vanilla ice cream. What percentage of students prefer strawberry ice cream?

Step	Description	Calculation
1	Find the ratio. Since 100 out of 250 students prefer strawberry ice cream, the ratio is 100 / 250.	100 / 250
2	Divide the ratio.	100 / 250 = 0.4
3	Multiply by 100.	0.4 · 100 = 40
4	Add the percent sign.	40%
Table 2: Convert a ratio to a percentage example 2

How to convert a percentage to a ratio

To convert a percentage to a ratio, remove the percent sign, divide the percentage by 100, then multiply by the total population. You may need to round the result to the nearest whole number.

Example 3: If 27% of voters voted for Jamathan Johnson and there were 64 voters, how many people voted for Jamathan Johnson?

Step	Description	Calculation
1	Remove the percent sign.	27% becomes 27.
2	Divide the percentage by 100.	27 / 100 = 0.27.
3	Multiply by the total population.	0.27 · 364 = 98.28.
4	Round to the nearest whole number.	98.28 rounded to the nearest whole number is 98.
5	98 of 367 voters voted for Jamathan Johnson.	98 / 367.
Table 3: Convert a percentage to a ratio

References

1. McAdams, David E.. All Math Words Dictionary, percent. 2nd Classroom edition 20150108-4799968. pg 136. Life is a Story Problem LLC. January 8, 2015. Buy the book

Cite this article as:

McAdams, David E. Percent. 4/28/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/p/percent.html.

Revision History

4/28/2019: Changed equations and expressions to new format. (McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
12/1/2018: Removed broken links, updated license, implemented new markup. (McAdams, David E.)
5/5/2018: Initial version. (McAdams, David E.)