Math

Instant, private, and free

Modulo Calculator.

Calculate a remainder and compare signed remainder with mathematical non-negative modulo.

On-device calculationNo signup
01

Set your values

Results update as you type.

How to Use

Enter a dividend and a non-zero divisor. Results update as you type.

JavaScript remainder (%) truncates the quotient toward zero and follows the dividend's sign.

Mathematical modulo is always between 0 (inclusive) and the absolute divisor (exclusive), including for negative inputs.

FAQs

What is the difference between remainder and modulo?

A signed remainder follows the dividend's sign, while mathematical modulo is normalized to a non-negative value below the absolute divisor.

Can the divisor be negative?

Yes. The signed remainder follows JavaScript's operator semantics, while mathematical modulo uses the absolute divisor for its non-negative range.

Cite this calculator

Canonical URL: https://mathify.one/ru/math/modulo

Cite as: Mathify. (2026). Калькулятор: Modulo. https://mathify.one/ru/math/modulo

Use Cases

Check remainder in programming

Quickly verify how JavaScript's % operator behaves with negative numbers, and compare it to the mathematical modulo for algorithm design.

Example: Check -7 % 3 vs -7 mod 3 to see -1 vs 2.

Learn modulo arithmetic

Understand the difference between signed remainder and non-negative modulo, useful for math homework or teaching.

Example: See that 10 mod 4 = 2, but -10 mod 4 = 2 (mathematical) vs -2 (JavaScript).

Frequently Asked Questions

What is the difference between JavaScript's remainder and mathematical modulo?
JavaScript's remainder operator (%) returns a result with the sign of the dividend, so -5 % 3 gives -2. Mathematical modulo returns a non-negative result, so -5 mod 3 gives 1. This calculator shows both for comparison.
How do I use this modulo calculator?
Enter a dividend and a divisor. The calculator will compute the remainder (JavaScript style) and the mathematical modulo (non-negative). It also shows the quotient and the division equation.
Can this calculator handle negative divisors?
Yes, it handles negative divisors. The mathematical modulo is always non-negative, while the JavaScript remainder takes the sign of the dividend. The calculator displays both results clearly.

Tips & Common Mistakes

Tips

  • Remember: JavaScript's % gives the remainder, not the mathematical modulo. For negative dividends, results differ.
  • Use the mathematical modulo when you need a result in the range [0, divisor-1], common in cyclic calculations.
  • Check both results to avoid bugs in code that relies on non-negative remainders.
  • The divisor cannot be zero; division by zero is undefined.

Common Mistakes to Avoid

  • Assuming JavaScript's % always returns a non-negative result; it returns the sign of the dividend.
  • Confusing the remainder with the modulo when dealing with negative numbers; they are not the same.
  • Forgetting that the divisor cannot be zero; entering zero will cause an error.

Last updated: August 13, 2026