Math Tools
Calculators and number converters - 6 tools
Number Base Converter
Binary, octal, decimal, hex, and any base to 36
Percentage Calculator
Six percentage calculations, updated as you type
Roman Numeral Converter
Numbers 1 to 3999 to Roman numerals and back
Scientific Calculator
Trigonometry, logs, powers, memory, and history
Fraction Calculator
Exact fraction arithmetic with the steps shown
Statistics Calculator
23 statistics: mean, median, quartiles, skewness
About Math Tools
Six calculators and number converters, each computing on the page as you use it. Fraction Calculator and Number Base Converter use exact arithmetic on whole numbers of any size, so 1/3 + 1/6 gives exactly 1/2. Scientific Calculator evaluates expressions with the mathjs library and shows 12 significant digits. Statistics Calculator turns a pasted list of numbers into 23 descriptive statistics, and Percentage Calculator solves six common percentage questions side by side.
How to use Math Tools
- 1Choose the calculator: percentages, fractions, statistics, a scientific expression, Roman numerals, or number bases.
- 2Type your numbers; Percentage Calculator, Roman Numeral Converter, and Number Base Converter update the answer as you type.
- 3In Scientific Calculator, type an expression or use its keypad, and choose radians or degrees for trigonometry.
- 4Read the result, and in Fraction Calculator the numbered steps that lead to it.
Frequently asked questions
How precise are the results?
12 significant digits in Scientific and Statistics Calculator, and 10 in Percentage Calculator. Fraction Calculator is exact and shows a repeating decimal in parentheses; Number Base Converter is exact and stops at 40 digits after the point, marked …, when a fraction never ends.
Does Scientific Calculator use degrees or radians?
Both: you choose the mode, and sin, cos, and tan follow it. The calculator also has log10, ln, square roots, powers, factorials, π, e, the Ans key, a memory, and the last 10 calculations.
Why does Roman Numeral Converter stop at 3999?
MMMCMXCIX, 3999, is the largest standard form: there is no symbol above M, and M repeats at most three times. The converter also refuses non-standard forms such as IIII.
Which statistics does Statistics Calculator give?
23 values, including the mean, geometric and harmonic means, median, mode, range, variance and standard deviation, quartiles computed inclusively or exclusively, skewness, kurtosis, and outliers.
Tips and tricks
- ✓Paste a column from a spreadsheet into Statistics Calculator: tabs, new lines, commas, and semicolons all separate values.
- ✓In Fraction Calculator, enter 1 3/4 as 1 in the small whole-number box, 3 as numerator, and 4 as denominator; a decimal such as 0.75 becomes an exact fraction.
- ✓Scientific Calculator keeps your last 10 calculations, and Ans reuses the previous result.
- ✓Percentage change divides by the absolute starting value, so going from -50 to -25 is a change of 50%.