Recipe scaling: 3/4 cup oil + 1/2 cup water - total liquid?
3/4 + 1/2. Common denominator: 4. So 3/4 + 2/4 = 5/4 cups = 1 1/4 cups total liquid. As decimal: 1.25 cups.
Add, subtract, multiply or divide two fractions and get the result simplified to its lowest terms - plus a decimal and percent equivalent. Mixed numbers (like 2 1/4) and improper fractions (like 9/4) are both supported. Designed for school homework, recipes, and any DIY measurement task that mixes fractions.
First fraction
Whole · Numerator / Denominator (set whole to 0 for a simple fraction)
Second fraction
Whole · Numerator / Denominator (set whole to 0 for a simple fraction)
Reduced fraction
7 / 4
Mixed: 1 3/4
Decimal
1.75
≈ 175%
Sebagian konten masih ditampilkan dalam bahasa Inggris.
Fractions show up in school math (Class 4-8 mathematics core), recipes (1/4 cup oil + 3/4 cup water), carpentry and DIY measurements (1/2 inch plywood vs 3/4 inch), engineering drawings, and many real-world ratios. Despite their everyday use, fraction arithmetic - especially addition and subtraction with different denominators - trips up students and adults alike. This calculator handles all four operations (+, −, ×, ÷) on fractions, supports both improper fractions (9/4) and mixed numbers (2 1/4) as inputs, and shows the result in multiple forms (reduced fraction, mixed number, decimal, percent).
Beyond simple computation, this tool is useful as a learning aid. The displayed formula shows the underlying method (common denominator for addition, reciprocal-multiply for division, etc.), and the multi-form result helps build intuition about how fractions, decimals and percents relate. Students preparing for board exams or competitive entrance tests can use it to verify homework answers; cooks scaling recipes can compute portions; DIYers can sum measurements without converting to decimals first.
Type the first fraction - numerator and denominator (and optional whole-number part for mixed numbers).
Pick an operation: + − × ÷.
Type the second fraction.
The result shows in reduced form, as a mixed number, decimal and percent.
Swap operands or change operation any time - the answer updates instantly.
All four operations work by first finding a common form, then reducing to lowest terms using the Greatest Common Divisor (GCD). Addition and subtraction need a common denominator (we use the product, then reduce). Multiplication multiplies straight across. Division flips the second fraction and multiplies. The Euclidean algorithm computes GCD efficiently even for very large numbers.
+: (a/b)+(c/d) = (ad+bc)/(bd) ×: (a/b)×(c/d) = ac/bd
Addition and subtraction require a common denominator. The calculator uses the product of the two denominators (b × d) as the common denominator, then computes (a×d + c×b)/(b×d) for addition and (a×d − c×b)/(b×d) for subtraction. The result is then reduced to lowest terms using the Greatest Common Divisor (GCD), computed via the Euclidean algorithm. Multiplication is straightforward: (a/b) × (c/d) = (a×c)/(b×d), then reduce. Division uses the reciprocal: (a/b) ÷ (c/d) = (a/b) × (d/c) = (a×d)/(b×c).
Mixed numbers (e.g., 2 1/4) are first converted to improper fractions before computation. The conversion: whole × denominator + numerator, all over denominator. So 2 1/4 = (2×4 + 1)/4 = 9/4. After the operation, the calculator can show the result both as an improper fraction (e.g., 7/4) and a mixed number (1 3/4) - Indian school textbooks vary in which form is preferred, so showing both removes ambiguity.
The Euclidean algorithm for GCD: GCD(a, b) = GCD(b, a mod b), repeating until the remainder is 0. Example: GCD(48, 36). 48 mod 36 = 12. GCD(36, 12) = GCD(12, 0) = 12. So 48/36 reduces by 12 → 4/3. The algorithm runs in logarithmic time, handling numerators and denominators of any reasonable size instantly.
3/4 + 1/2. Common denominator: 4. So 3/4 + 2/4 = 5/4 cups = 1 1/4 cups total liquid. As decimal: 1.25 cups.
5 × 7/8 = 35/8 = 4 3/8 inches = 4.375 inches. Useful when planning stacked board projects.
1 1/3 × 600. Convert mixed to improper: 4/3. So 4/3 × 600 = 2400/3 = ₹800. Verify: 1 hour = ₹600, extra 1/3 hour = ₹200, total ₹800.
Multiply each fraction by the form of 1 needed to give a common denominator. Example: 1/3 + 1/4 → multiply first by 4/4 and second by 3/3 → 4/12 + 3/12 = 7/12. The calculator does this automatically and reduces if needed.
Multiply the whole part by the denominator, add the numerator, keep the denominator. Example: 2 3/4 = (2 × 4 + 3)/4 = 11/4.
Divide the numerator by the denominator. The quotient is the whole part, the remainder over the denominator is the fractional part. Example: 11/4 = 2 remainder 3 → 2 3/4.
Divide numerator and denominator by their GCD. Example: 18/24 → GCD(18, 24) = 6 → 3/4. Already-reduced fractions like 7/12 stay the same.
0.333... (repeating). The calculator shows 0.333333 by default. As a percent, that's 33.3333%.
No. Division requires a non-zero second fraction (numerator can be zero, denominator cannot). The calculator flags an undefined result if you try.
Both forms are correct as long as they reduce to the same fraction. Some textbooks leave answers as improper fractions (e.g. 7/4), others convert to mixed numbers (1 3/4). This calculator shows both.
From simple percentages to scientific notation, statistics, geometry and big-number arithmetic - every common math problem you'd reach for a calculator for, runs in your browser with no installs. The fraction calculator preserves exact rationals, the big-number calculator uses BigInt for hundreds of digits without precision loss, and the scientific calculator's expression evaluator is a hand-written shunting-yard parser (no eval) that supports trig, log, factorial and parentheses.
If you're a student, double-check your work without paying for a graphing calculator. If you're a professional, use these tools as a sanity check on spreadsheet formulas. Every result is shown alongside its formula and inputs, so the math is always auditable.
The Fraction Calculator is part of the Math suite on Online Calculator Tools, alongside 6 related calculators. All tools share the same UI patterns, the same privacy-first rendering (nothing is sent to a server), and the same commitment to showing the formula and assumptions behind every result.