Ratio is a term that means the comparison of two units or numbers to each other. In the lower grades of school, ratio is taught as a comparison of the same types of units. Ratio is actually the basis for rate and other comparison terms in mathematics. An example of how ratio is taught would be as following. A family has 2 boys and 3 girls. The ratio of boys to girls is 2:3 or 2/3.
Rate is a comparison of two different types of units. It is actually a ratio. For example, a person earns $120 for working an 8 hour day. The rate that the person earned per hour is $120/8 or $15 per hour. Rate is encountered by people when they decide how early to leave for work. The amount of time it takes to drive x amount of miles to work is a rate known as miles per hour.
Ratio is actually the basis for other comparisons. Rate is a ratio. A ratio that is a complex fraction determined per 100 is called a percentage. An equality of ratios is called a proportion. Fractions are ratios that are stated, for example, as x part to y parts.
Miles per hour is the amount of miles that is traveled in an hour. Miles per gallon is computed by the ratio of miles traveled to the miles of fuel used or miles traveled/fuel used. The hourly wage is a rate that is determined by the amount earned in a day divided by the number of hours. Lending rate is an amount of money that a lender will charge to loan money.