General Math Calculator
A collection of commonly used math utility calculators: prime factorization, permutations and combinations, logarithms, and angle conversion.
Prime Factorization Calculator
Enter a natural number to find its prime factors and exponents, the basis for GCD and LCM....
Read MorePermutation & Combination Calculator
Enter the total (n) and chosen (r) to calculate permutations (nPr) and combinations (nCr)....
Read MoreAngle Converter Calculator
Convert degrees to radians and radians to degrees, with the common angles (30°, 45°, 60°, ...
Read MoreAbout This Category
Four tools that show up constantly in study and in code: prime factorisation, permutations and combinations, logarithms, and angle conversion between degrees and radians. Each has a rule that decides whether the answer is right.
The distinction that matters most is order: permutations count arrangements where order matters, combinations count selections where it does not. A lottery draw is a combination; a podium is a permutation.
Frequently Asked Questions
What is the difference between nPr and nCr?
nPr counts ordered arrangements, nCr unordered selections. Choosing 3 from 10 gives 720 permutations but only 120 combinations, because each selection can be arranged six ways.
Why is the logarithm of a number between 0 and 1 negative?
Because the log answers "what power of ten gives this number", and 0.1 is 10⁻¹. The logarithm is only defined for positive inputs.
Do programmers use degrees or radians?
Most programming languages use radians for trigonometry, while people describe angles in degrees. Convert before calling a trigonometric function.
Calculators in This Category
Sources & last update
2026-10-19