Add, subtract, multiply and divide fractions or decimals. Get an exact simplified answer, a rounded decimal and the steps, directly in your browser.
Add, subtract, multiply or divide two fractions or decimal values. Use integer numerators and denominators (e.g., 1/2), or enter a decimal such as 0.5. Results include a simplified fraction and a decimal rounded to six places.
Enter a whole number, a decimal such as 0.25, or an integer fraction such as 3/8. A negative sign can appear on the numerator or denominator. Choose an operation and select Calculate. A denominator must not be zero; dividing by a fraction equal to zero is also undefined.
Mixed-number notation is not accepted: enter 7/4 instead of 1 3/4. For a decimal denominator, rewrite 1/0.5 as 2 before entering it. Each input supports up to 200 characters. Results keep exact integer arithmetic; the accompanying decimal is rounded to six places.
Use a common denominator of 20. Convert 2/5 to 8/20 and 1/4 to 5/20. Adding the numerators gives 13/20, or 0.650000. The denominator describes the size of each part; it is not added to the other denominator.
Multiply 5/6 by the reciprocal 3/2: 15/12. Divide numerator and denominator by 3 to obtain 5/4, or 1.250000. A result larger than one is valid.
Entering 0.1 + 0.2 gives 3/10. The calculator treats these inputs as 1/10 and 2/10, avoiding binary decimal rounding in the exact answer.
The fraction is reduced by the greatest common divisor. A denominator of one is shown as a whole number. The decimal is a display approximation: 1/3 is exactly one third even though the displayed decimal ends at 0.333333. Very small nonzero fractions can round to 0.000000, so use the exact fraction when precision matters.
These rules cover arithmetic on rational numbers; they do not solve equations or operate on algebraic expressions. Reference: fraction arithmetic and simplification.
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Reviewed September 15, 2026. Calculation methods and corrections.