Number Tools
Work with numbers the way homework, invoices and legal documents actually need them: spelled out in words, written as Roman numerals, factorised, or checked for primality.
All Number Tools (22 Available)
Average Calculator
Mean, sum and count from any list of numbers.
Mean, Median and Mode Calculator
All three measures of central tendency from one data set.
Standard Deviation Calculator
Population and sample standard deviation, variance and more.
Fraction Calculator
Add, subtract, multiply and divide fractions with the steps shown.
Ratio Calculator
Simplify ratios, scale them up and solve for a missing value.
Scientific Calculator
A full scientific calculator with memory and history.
Number Base Converter
Convert numbers between binary, octal, decimal, hex and any base.
Binary to Decimal Converter
Convert binary numbers to decimal with the working shown.
Decimal to Binary Converter
Convert decimal numbers to binary with the division steps.
Hex to Decimal Converter
Convert hexadecimal numbers to decimal.
Decimal to Hex Converter
Convert decimal numbers to hexadecimal.
Random Number Generator
Generate random numbers in any range, unique or repeating.
Prime Number Checker
Check whether a number is prime and see its factors.
Factorial Calculator
Calculate exact factorials, permutations and combinations.
LCM and HCF Calculator
Find the lowest common multiple and highest common factor.
Number to Words Converter
Spell out numbers in words, international or Indian scale.
Roman Numeral Converter
Convert numbers to Roman numerals and back.
Square Root Calculator
Find square roots, cube roots and any nth root.
Scientific Notation Converter
Convert between standard, scientific and engineering notation.
Rounding Calculator
Round numbers by decimals, significant figures or nearest multiple.
Fibonacci Sequence Generator
Generate Fibonacci numbers and explore the golden ratio.
Decimal to Fraction Converter
Convert decimals and percentages to exact fractions.
About Number Tools
Number-to-words conversion supports both the international scale (million, billion, trillion) and the Indian scale (lakh, crore), because cheques and invoices in different countries require different wording.
Primality testing uses trial division for small inputs and a deterministic Miller-Rabin test with BigInt arithmetic for large ones, so results are exact rather than probabilistic.
LCM and HCF use the Euclidean algorithm, which stays fast even for very large integers, and the tool shows the prime factorisation alongside the answer so it can be used as a study aid.
Number Tools FAQs
How large a number can these tools handle?
Tools that need exact integers use JavaScript BigInt, so they handle numbers with hundreds of digits. Tools that work with decimals are limited to double precision, about 15 significant digits.
What is the difference between lakh/crore and million/billion?
They are different digit groupings. The Indian system groups after the first three digits in twos — 1,00,000 is one lakh, 1,00,00,000 is one crore. The international system groups in threes — 100,000 and 10,000,000. Our converter supports both.
Is 1 a prime number?
No. A prime has exactly two distinct positive divisors, and 1 has only one. Excluding it is what makes the fundamental theorem of arithmetic — unique prime factorisation — hold.
How do you write 4 in Roman numerals?
IV, using subtractive notation. Our converter follows the standard modern form used for dates and copyright notices, which covers 1 to 3,999.