GCD of multiple numbers
Enter three or more whole numbers and see their greatest common divisor, with the steps: the GCD of the first two, then of that result and the next number, and so on.
Whole numbers, separated by a semicolon, comma or space.
Fill in the fields; the answer appears here straight away.
How it's worked out
How it works
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Enter the values
Type the numbers or the formula. Decimals may use a point or a comma. No idea? Click Fill in an example.
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Instant answer
The answer appears as you type, with the most important intermediate values.
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See the working
Under "How it's worked out" you see the steps, handy for checking your own calculation.
How does it work with more numbers?
The GCD of several numbers is found step by step, because GCD(a, b, c) = GCD(GCD(a, b), c). For 84, 126 and 210:
- GCD(84, 126) = 42
- GCD(42, 210) = 42
So 42 is the largest number that divides all three. If the GCD reaches 1 along the way, the answer is 1: the numbers have no common factor.
When is it useful?
To simplify a ratio (84 : 126 : 210 = 2 : 3 : 5), to find the largest tile size that fits several lengths, or to share several amounts into equal groups. For two numbers with Euclid's steps, use the GCD calculator. For the smallest common multiple, use the LCM calculator.
Frequently asked questions
Is the GCD of multiple numbers free?
Yes. The GCD of multiple numbers is completely free, with no account, sign-up or usage limit.
How accurate is the result?
The tool calculates with your browser's number precision. For important calculations, always double-check what you entered.
Does it work on my phone?
Yes. The tool works in any modern browser on a phone, tablet or computer.