Fraction Calculator

A fraction calculator handles the four basic operations on fractions (addition, subtraction, multiplication, division) and simplifies the result to lowest terms automatically. It also returns the decimal equivalent and, where applicable, a mixed number form. Useful for cooking, woodworking, school homework, or any context where numbers are most naturally expressed as parts of a whole.

Fraction math has rules that don't look like ordinary arithmetic. You can't just "add the tops and bottoms" — that's the most common student mistake. The rules look strange because fractions are really division in disguise: 3/4 means "three divided by four," and the operations have to preserve that meaning.

Recipe scaling: A recipe needs 2/3 cup of flour, but you're tripling it.

• (2/3) × 3 = 6/3 = 2 cups

Carpentry: Two boards measure 3/4 inch and 5/8 inch. Total thickness?

• 3/4 + 5/8 → common denominator 8 → 6/8 + 5/8 = 11/8 = 1 3/8 in

Splitting a bill: 1/4 of $80 split among 3 friends.

• (1/4) × 80 = 20 → 20 ÷ 3 = $6.67 each

Reducing: 24/36 simplifies to what?

• GCD(24, 36) = 12 → 24/12 over 36/12 = 2/3

• Cooking and baking — scaling recipes up or down.
• Woodworking and DIY — adding measurements that come in 1/8, 1/4, 1/16 inch increments.
• Schoolwork — homework, exams, standardized tests.
• Sewing and quilting — calculating yardage and pattern adjustments.
• Music — note durations are fractions (1/2 note, 1/4 note, 1/8 note).

• Adding tops and bottoms straight. 1/2 + 1/3 ≠ 2/5. You need a common denominator first.
• Forgetting to simplify. 4/8 is correct but messy. Reduce to 1/2.
• Mixing operations. Multiplication doesn't need a common denominator; addition does. Don't apply the wrong rule.
• Dividing by flipping the wrong one. When dividing a/b by c/d, flip the second (c/d), not the first.
• Mishandling negative fractions. A negative sign can go on the numerator, denominator, or in front of the whole fraction — they all mean the same thing. Standard convention puts it in front: −3/4.