Math calculators

Percentages in every phrasing, exact fractions, the rule of three, Roman numerals, numbers written out in words, splitting the bill and counting words and characters. Quick answers to everyday sums.

• Fraction Calculator

  Add, subtract, multiply and divide fractions: exactly, never rounded.

• Proportion Calculator

  Solve a proportion, including the inverse case the usual formula gets wrong.

• Roman Numeral Converter

  Turn any number from 1 to 3999 into Roman numerals, and see how it is built.

• Roman Numerals to Numbers

  Read any Roman numeral, and get told when what you typed is not one.

• New

  Number to Words

  Any number or dollar amount in words, the way it goes on a check.

• Percentage Calculator

  What is X% of Y: the everyday percentage, worked out step by step.

• Percentage Increase

  Add a percentage to a value, or find the increase between two numbers.

• Discount Calculator

  The price after a discount, and the price before it, from the sale tag.

• Tip Calculator

  The tip, the total and what each person owes (including the cent that does not divide).

• Percentage Difference

  How far apart two values are, with neither one as the reference.

• Percentage of a Total

  X is what percent of Y: the share one number is of another.

• Word Counter

  Words, characters, sentences and reading time, counted as you type.

• Character Counter

  Characters with and without spaces, against the X and meta description limits.