Modulo Calculator
Divide one number by another and see both the integer quotient and the remainder (the modulo result). This free online developer calculator runs entirely in your browser — no signup, no data sent anywhere.
Inputs
Results
How It Works (Formula & Method)
For inputs a and b, the integer quotient is floor(a ÷ b) and the remainder is a − (quotient × b). For example, 17 ÷ 5 gives a quotient of 3 with a remainder of 2, because 3 × 5 = 15 and 17 − 15 = 2.
Worked Example
Below is a worked example using the calculator's default values. The same numbers are pre-filled in the form above so you can press Calculate and see the result without typing anything.
Inputs used:
- Dividend (a): 17
- Divisor (b): 5
With these inputs, the calculator computes the metrics shown in the Results panel. Change any value and press Calculate again to see how the result responds — the live widget and the chart both update instantly.
About the Modulo Calculator
The modulo operation returns the remainder left over after dividing one integer by another. It is one of the most-used operations in programming — for wrapping array indices, checking divisibility, alternating colors in a list, hashing, and clock arithmetic. This calculator shows both the remainder and the whole-number quotient.
Tips & Considerations
- A number is even when n mod 2 equals 0, and divisible by k when n mod k equals 0.
- Modulo wraps values into a range — index mod length always lands inside a zero-based array.
- Languages disagree on the sign of the result for negative operands. This tool uses the JavaScript convention, where the result takes the sign of the dividend.
Frequently Asked Questions
What is the modulo operator in code?
In most languages it is the percent sign: <code>a % b</code>. It returns the remainder of dividing a by b.
How does modulo handle negative numbers?
It varies by language. JavaScript and C return a result with the sign of the dividend, so −7 % 3 is −1. Python returns a result with the sign of the divisor, giving 2.
Why is modulo used for "every Nth item"?
When a counter mod N equals 0, the counter is an exact multiple of N — a clean way to trigger an action every N iterations of a loop.
What does the Modulo Calculator compute?
The Modulo Calculator takes 2 input values and returns 2 results. Find the remainder and integer quotient of a division — the modulo operation used throughout programming.