How to use this calculator

Cross-multiply, add the numerators, then reduce the result.

The method

a/b + c/d = (ad + bc) / bd

Enter your values in the labeled fields and choose Calculate. The result panel shows the answer and supporting values when useful.

WORKED EXAMPLE INPUT

First numerator: 3, First denominator: 4, Second numerator: 5, Second denominator: 6

Select Calculate to evaluate these example values.

Scope and limitations

Denominators cannot be zero. Whole-number numerator and denominator inputs are recommended.

Common questions

Can I change the example values?

Yes. Replace every prefilled value with your own inputs and calculate again.

Are displayed results exact?

Some results are rounded for readability. Keep extra precision when the next step depends on the result.

Methods & verification

Formulas use standard mathematical definitions and fixed unit factors where applicable. See our methodology for numerical conventions, rounding, privacy, and limitations.