Factor Calculator – Find All Factors of a Number
List all positive factors of a whole number.
About the Factor Calculator
What is the Factor Calculator?
A factor calculator lists every positive whole number that divides evenly into a target number.
Why use this calculator?
Factoring is the backbone of simplifying fractions, finding roots and solving puzzles — and it is exactly how trial division of numbers works.
How to use it
- Enter a whole number.
- Read the full, sorted list of its factors.
- Also see the proper-divisor sum and whether the number is prime.
Formula
Loop i from 1 to √n, pair each divisor with its partner.
Includes the number itself. For prime factorization use the prime factorization calculator.
Frequently Asked Questions
Is 0 a factor of anything?
Every number has factor pairs including both a positive and negative version. Zero is never a factor.
How many factors does a prime have?
Exactly two: 1 and itself.
What order of operations does this use?
It follows standard PEMDAS/BODMAS rules: parentheses, exponents, multiplication and division, then addition and subtraction.
How precise are the answers?
The calculator uses double-precision floating-point math (about 15 significant digits) and rounds the display. For exact symbolic results use dedicated algebra software.
Can I enter negative numbers or decimals?
Yes. Negative values, decimals and very large or small numbers are all supported unless a field says otherwise.
What does it mean if I get an error?
Errors usually mean an invalid input, such as division by zero or a negative value where only positives make sense. Check your entries and try again.
Is this calculator free to use?
Yes. Every calculator on this site is completely free, with no hidden fees, no subscriptions and no limits on how many times you can use it.
How accurate are the results?
We use standard, widely accepted formulas and calculate in your browser using double-precision arithmetic. Results are rounded for readability, so treat them as reliable estimates rather than a guarantee. Real-world factors can vary the true figure.
Can I add this calculator to my own website?
Yes. Open this calculator page and use the "Add to your website" box in the sidebar to copy a ready-made iframe snippet, then paste it into any HTML page.
Does it work on a phone or tablet?
Yes. The layout is fully responsive, so it works on desktops, laptops, tablets and mobile phones, and every input adapts to touch screens.