Factor Calculator
Quickly find your Factor list with our free Factor Calculator. Simple, fast, and accurate.
Number
Factors
What is a Factor Calculator?
A Factor Calculator finds all the factors (divisors) of a given number. It lists every whole number that divides the input number exactly, making it quick to identify factor pairs, the total factor count, and whether the number is prime or composite.
How to calculate factors manually (the formula)
To find all factors of a number n, test every integer from 1 up to the square root of n. For each integer i where n ÷ i leaves no remainder, record both i and n ÷ i. Finally, sort the list in ascending order.
Example calculation
Find all factors of 60. The square root of 60 is about 7.7. Test 1 through 7. Factors are: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60. There are 12 factors total.
Common mistakes
- Forgetting 1 and the number itself — Every number has 1 and itself as factors. Always include them.
- Stopping too early — Only test up to the square root, but record the matching pair for each factor found.
- Including non-integer factors — Factors are always whole numbers. Decimals and fractions are not factors.
Frequently asked questions
What is a factor?
A factor of a number is a whole number that divides it exactly with no remainder.
How do I list all factors of a number?
Find all pairs of numbers that multiply to give your number.
Is 1 a factor of every number?
Yes, 1 is a factor of every whole number.
What is the difference between a factor and a multiple?
Factors divide a number exactly; multiples are what you get when you multiply a number by an integer.
How do I check if a number is prime using factors?
A prime number has exactly two factors: 1 and itself.