Add, subtract, multiply, or divide fractions, or convert a fraction to a decimal.
Frequently Asked Questions
How do you add or subtract fractions with different denominators?
Cross-multiply to find a common denominator, add or subtract the resulting numerators, then simplify using the greatest common divisor.
How do you divide fractions?
Multiply the first fraction by the reciprocal (flip) of the second fraction.
How do I convert a fraction to a decimal?
Divide the numerator by the denominator. For example, 3/4 = 3 divided by 4 = 0.75.
How fraction operations are calculated
Adding and subtracting fractions cross-multiplies to find a common denominator; multiplying just multiplies numerators and denominators directly; dividing multiplies by the reciprocal of the second fraction. Every result is automatically simplified using the greatest common divisor.
How to use this fraction calculator
- Enter your two fractions.
- Choose an operation: add, subtract, multiply, or divide.
- Click Calculate to see the simplified result and its decimal equivalent.
Need just a fraction-to-decimal conversion? Use the second tab and enter a single fraction.
Why fractions need a common denominator
You can only add or subtract fractions directly once they share the same denominator, because the denominator tells you what size „piece“ the numerator is counting — you can’t add thirds and quarters together until you convert them to a shared unit, like twelfths. This calculator handles that conversion automatically by cross-multiplying, then simplifies the result to its lowest terms using the greatest common divisor.
Common fraction operations explained
- Adding and subtracting: Convert to a common denominator first, then add or subtract the numerators.
- Multiplying: Multiply numerators together and denominators together — no common denominator needed.
- Dividing: Multiply the first fraction by the reciprocal (flipped version) of the second.
- Converting to decimal: Simply divide the numerator by the denominator.
Tips for working with fractions
Always check whether your final answer can be simplified further — this calculator does it automatically, but it’s a useful habit for manual work too. When a problem gives you a decimal and a classroom or worksheet expects a fraction, the „fraction to decimal“ mode can help you sanity-check your work in reverse.
Expert insight: the fraction-to-100 relationship
Khan Academy’s math curriculum, used by millions of students worldwide, teaches fractions, decimals, and percentages as three views of the same underlying number rather than separate topics — a fraction converts to a decimal by dividing, and to a percentage by multiplying that decimal by 100. Seeing the connection between all three makes it much easier to sanity-check a fraction calculation, like this tool’s decimal-conversion mode, against a percentage or decimal you already have an intuition for.
Further reading: Grocery Prices Are Splitting in Two Directions in 2026 — Here’s What It Means for Your Recipes
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Disclaimer: This calculator is provided for general informational and educational purposes only and does not constitute financial, investment, tax, or legal advice. Results are estimates based on the values you enter and should not be relied upon as the sole basis for any financial or other decision. Past performance and projected figures are not a guarantee of future results. Always consult a qualified professional before making financial decisions. See our Legal Notice and Privacy Policy for more information.