Fractions Calculator

Add, subtract, multiply, or divide any two fractions and get the answer as a reduced fraction and decimal. Free, instant, no signup.

Formula: a/b + c/d = (ad + bc) / bd (then reduce by GCD)

How to use the Fractions Calculator

  1. Enter your values. Fill in the fields with your numbers.
  2. Calculate. Press Calculate to run the fractions calculator.
  3. Use the result. Copy the result or try a related tool next.

Why use our Fractions Calculator

Instant results. Enter your figures and the fractions calculator returns an answer in seconds.
Free & private. Runs in your browser — no signup, and nothing is sent to a server.
Accurate. Uses standard formulas so you can rely on the numbers.

Free to use — premium coming soon

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About the Fractions Calculator

The Fractions Calculator takes two fractions and a single operation (add, subtract, multiply, or divide) and returns the answer reduced to its lowest terms, shown as both an improper fraction and a mixed number where it applies. You enter a numerator and denominator for each value, pick the sign, and it handles the arithmetic that trips people up by hand: finding a common denominator, combining numerators, and cancelling common factors. It works with proper fractions, improper fractions, and mixed numbers, so 1 1/2 plus 2/3 is just as easy as 7/8 minus 1/4.

Reach for this tool whenever a measurement, recipe, or schoolwork problem refuses to land on a whole number. Cooks scaling a recipe up or down multiply fractional cups and teaspoons; a 3/4 cup at two-thirds of the batch becomes 1/2 cup. Woodworkers and DIYers add board widths and saw kerfs measured in eighths and sixteenths of an inch. Students checking homework can confirm an answer and, just as usefully, see the simplified form they were expected to write. Anywhere unlike denominators appear, the calculator removes the bookkeeping and the risk of an arithmetic slip.

Under the hood it follows the standard formulas. Addition uses a/b + c/d = (ad + bc) / bd and subtraction uses a/b - c/d = (ad - bc) / bd; multiplication is numerator times numerator over denominator times denominator; division flips the second fraction and multiplies by its reciprocal. The raw result is then reduced by dividing the top and bottom by their greatest common divisor (GCD), and any improper fraction is rewritten as a whole number plus a remainder fraction. Mixed numbers are converted to improper fractions before the math, then converted back.

Because fractions are exact ratios of integers, this calculator works with whole-number arithmetic rather than decimals, so there is no rounding error: 1/3 stays 1/3 instead of becoming 0.333. The only limits are the size of the integers involved and division by zero, which is undefined and rejected. Everything runs in your browser, so the numbers you type are never sent to a server or stored. You can clear the form or close the tab and nothing is kept.

Frequently asked questions

How does the calculator add fractions with different denominators?

It rewrites both fractions over a common denominator, adds the numerators, then reduces the result. Using the formula a/b + c/d = (ad + bc) / bd, for example 1/2 + 1/3 becomes (3 + 2) / 6 = 5/6.

Can I enter mixed numbers like 2 1/4?

Yes. Mixed numbers are converted to improper fractions before the calculation (2 1/4 becomes 9/4) and the answer is offered back as a mixed number whenever the result is larger than one whole.

Does it always simplify the answer to lowest terms?

Yes. After computing the result it divides the numerator and denominator by their greatest common divisor, so 6/12 is shown as 1/2. You get the fully reduced form automatically.

How does dividing fractions actually work here?

Dividing by a fraction is the same as multiplying by its reciprocal, so the tool flips the second fraction and multiplies. For instance 1/2 divided by 3/4 becomes 1/2 times 4/3 = 4/6, which reduces to 2/3.

Is the result exact or rounded?

It is exact. The calculator works with whole-number numerators and denominators rather than decimals, so values like 1/3 are never rounded off and no precision is lost.

From our blog

How to Use a Days From Today Calculator to Hit Every Deadline

By the Super Simple Digital Tools Team · Updated June 2026

Most deadlines arrive as a duration, not a date. A contract says payment is due 'within 30 days', a store offers a '90-day return policy', a notice period is '14 days', a tax rule gives you '180 days'. Each of these is useless on a calendar until you convert it into a real date you can act on. That conversion is exactly what a Days From Today Calculator does: it anchors the count to today's date and tells you the precise day the clock runs out, so you can schedule reminders, reply to emails, and plan around it with confidence.

The mechanics are simple. Enter the number of days, pick a direction (forward for future deadlines, backward for questions like 'what date was 60 days ago'), and read the result. The tool adds or subtracts the days from today and resolves the answer across month lengths, year boundaries, and leap years that manual counting tends to botch. Quick presets such as 7, 14, 30, 60, and 90 days cover the periods people request most, and the output names the weekday so you immediately see whether the date is workable or falls on a weekend.

The single biggest source of error is the counting convention, not the arithmetic. 'Within 10 days' can mean ten calendar days or ten business days, and it can start counting from today or from tomorrow. Always check the source rule. Legal and financial deadlines frequently count in calendar days but then push to the next business day if the final day is a weekend or holiday; shipping and processing windows are often quoted in business days from the start. Decide which convention applies before you trust the number, because a single misread can put you a day or more off.

Business days deserve special attention. A plain days-from-today count keeps weekends in, so a 30-calendar-day window and a 30-business-day window land on very different dates, often more than a week apart. If your deadline is defined in working days, use a business-day mode that strips out Saturdays and Sundays, and remember that public holidays may extend the window further depending on the rule. When in doubt, calculate both and note which one the underlying agreement actually specifies.

Once you have the exact date, make it stick. Copy it into your calendar with a reminder a few days early, and for important deadlines build in a buffer rather than aiming for the final day, since mail, payments, and approvals rarely clear instantly. Because the calculator runs locally in your browser using your device clock, you can check sensitive contract or legal dates without sending anything to a server, then move straight to acting on the date instead of double-checking your counting.

  • Confirm whether your deadline counts in calendar days or business days before trusting the result, as the two can differ by a week or more.
  • If a rule counts the start date as day one, subtract one day from your input so the tool's day-zero default lines up.
  • Check the weekday in the output: a deadline landing on a Saturday or Sunday often shifts to the next business day for payments and filings.
  • For high-stakes dates, target a few days before the calculated deadline to absorb mailing, processing, or approval delays.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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