To use the Basic Percent Calculator, enter an amount in the first field, tab or click out of it, and then do the same in the second field. The answer will display automatically.

A common practice after an evening meal at a fine restaurant is to calculate the tip for the waiter or waitress. Based on how well we liked the service, we come up with a gratuity that’s usually based on a percentage of the bill.

The Basic Percent Calculator at the top of this page and on the home page of Percent Calculators finds the percentage of a known amount, just like how you would in calculating a tip. So, how does the Basic Percent Calculator work?

Finding the Percent of a Known Number

It’s very simple. This calculator finds the percentage of a known number by taking that number and multiplying it by the percent converted to decimal format. Here’s the basic formula:

Formula: (Known Number) x (Percent Converted to Decimal) = Answer

For further clarity, a few examples follow.

Example 1: Bill was exceptionally pleased with the food and service at a new restaurant and decided to tip 20% instead of his normal 15%. The bill was $48.54. What is the tip amount?

Solution: Sticking the two into the Basic Percent Calculator quickly returns the answer, in this case the tip, of 9.71.

Answer: To get that amount, we first convert 20% to an equivalent decimal by stripping the percent sign and diving it by 100. The result is 0.20. That is then multiplied by the $48.54 bill to get the 9.71 tip amount.

Formula Completed: 20/100 x 15.42 = 9.71

Example 2: Jim has $112 to spend but he must also consider an 8.25% sales tax. How much does Jim really have to spend?

Solution: Entering the sales tax percent and Jim’s money amount into the Basic Percent Calculator shows $9.24 for the sales tax.

Answer: In manually calculating the amount, we must first convert 8.25% to decimal format by dividing it by 100. The 0.0825 result is then multiplied by $112 to get the sales tax amount of $9.24.

Percentage Formula Completed: 8.25/100 x 112 = 9.24

The final step in this particular example is to subtract the sales tax amount of $9.24 from Jim’s $112 to find the actual amount he can spend, which is $102.76.