Fraction Calculator
Last updated: June 13, 2026Add, subtract, multiply and divide fractions.
The Fraction Calculator adds, subtracts, multiplies and divides two fractions and instantly shows the answer reduced to lowest terms, alongside its decimal value. Type a numerator and denominator for each fraction, tap +, −, × or ÷, and the result updates live — no Calculate button, no sign-up, no ads in your way. It runs entirely in your browser, so nothing you enter is uploaded, making it a fast, private helper for homework and everyday math.
How to use Fraction Calculator
Using the Fraction Calculator takes seconds and needs no setup. You enter two fractions as numerator/denominator pairs, choose one of the four operations, and read the simplified answer and its decimal equivalent in the result panel. Everything recalculates the moment you change a number or operator, so you can experiment freely and check several problems in a row without reloading.
Read the full guide: How to Calculate Fractions (Add, Subtract, Multiply)
- 1Type the top and bottom numbers of Fraction A into its two boxes (for example 1 and 2 for one-half).
- 2Tap +, −, × or ÷ to pick whether you want to add, subtract, multiply or divide.
- 3Enter Fraction B the same way and read the reduced answer in the Result panel.
- 4Check the line below the result for the decimal value, rounded to four places.
Always fully reduced
Every answer is divided by the greatest common divisor of its numerator and denominator, so you get 1/2 rather than an unsimplified 4/8.
Decimal shown too
Below each fraction result you also see its decimal value to four places, with trailing zeros trimmed, so 3/4 reads cleanly as 0.75.
Live, no button
Results update the instant you edit any numerator, denominator or operator, letting you re-check many problems back to back without clicking Calculate.
Add fractions for a recipe
Doubling or combining recipe amounts often means adding fractions like 2/3 cup plus 3/4 cup. Enter both, tap +, and you get 17/12, which the decimal line reads as about 1.4167 cups — enough to know you need roughly one and a half cups without juggling common denominators by hand.
Check fraction homework with steps
Students learning to add, subtract, multiply and divide fractions can verify each answer instantly and see it reduced to lowest terms. Comparing the simplified fraction and its decimal helps confirm whether an answer like 6/8 should really be written as 3/4, reinforcing the simplifying step rather than just the arithmetic.
Convert a fraction to a decimal
Set Fraction B to 1/1 and any operation, or simply divide the fraction by itself's parts, to read a fraction's decimal value directly in the result panel. The calculator rounds to four places and trims trailing zeros, so 5/8 shows as 0.625 — handy when a measurement or grade needs a decimal form.
Scale measurements in woodworking
Shop and DIY projects frequently combine inch fractions such as 5/16 and 1/8. Subtracting or adding them here returns an exact reduced fraction plus a decimal, so you can mark 7/16 of an inch or read 0.4375 on a digital caliper without converting to a common denominator yourself.
Fraction Calculator — frequently asked questions
How does it add and subtract fractions with different denominators?
It cross-multiplies: the new numerator is a1×b2 ± a2×b1 and the new denominator is b1×b2, giving a common denominator automatically. It then divides both by their greatest common divisor to reduce the result to lowest terms.
How are multiplication and division handled?
Multiplication multiplies the numerators together and the denominators together. Division flips the second fraction and multiplies, so a/b ÷ c/d becomes a×d over b×c. The answer is then simplified the same way.
Is the result always reduced to lowest terms?
Yes. After computing the raw numerator and denominator, the calculator runs the Euclidean algorithm to find their greatest common divisor and divides both by it. A denominator of 1 is shown as a whole number.
Does it handle negative fractions?
Yes. You can enter negative numerators or denominators, and the calculator moves the sign to the numerator so results display in standard form. A zero denominator is invalid and shows a dash instead of an answer.
Are my calculations private?
Completely. All arithmetic runs in JavaScript inside your browser. Nothing you type is sent to a server, stored, or logged, and the tool works without an account or any uploads.
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