Number Tools
Percentages, averages, ratios, random numbers, Roman numerals and number bases. 11 free tools. Each one runs in your browser, shows a worked example table, and explains how it gets its answer.
Try it now: Percentage Calculator: What Is X% of Y?
Percentage of a number
Fill both boxes; the answer updates at once.
Answer
12
15% of 80 = 12
In words
92
Number plus the percentage
68
Number minus the percentage
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All number tools
- Percentage Calculator: What Is X% of Y?Find a percentage of any number
- What Percent Is X of Y?Find what percent one number is of another
- Percent Change CalculatorFind the percent increase or decrease between two numbers
- Average Calculator (Mean, Median, Mode)Mean, median, mode, range and standard deviation of a list
- Random Number GeneratorDraw random whole numbers from a range, with or without repeats
- Roman Numeral ConverterConvert numbers to Roman numerals and back
- Number to Words ConverterWrite a number out in words, with its ordinal form
- Number Base ConverterConvert numbers between binary, octal, decimal, hex and base 36
- GCD and LCM CalculatorGreatest common divisor and least common multiple of a list
- Percentage Increase and Decrease CalculatorIncrease or decrease a number by a percentage
- Ratio SimplifierReduce a ratio such as 1920:1080 to 16:9