Egyptian Fraction Calculator

Convert any fraction or decimal into a sum of distinct unit fractions (1/n) using the Egyptian Fraction Calculator. See every greedy algorithm step instantly.

993.3K uses Updated · 2026-05-04 Runs locally · zero upload
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How to Use Egyptian Fraction Calculator

The Egyptian Fraction Calculator lets you decompose any positive fraction or decimal into a sum of distinct unit fractions of the form 1/n. Choose your input mode — fraction or decimal — fill in the values, and the Egyptian Fraction Calculator instantly displays every step of the greedy algorithm alongside the final result.

  1. Select input mode — choose “Fraction” to enter a numerator and denominator, or “Decimal” to enter a decimal value such as 0.8333.
  2. Enter values — type the numerator and denominator (for fraction mode) or the decimal (for decimal mode). Both proper fractions (a < b) and improper fractions (a ≥ b) are supported.
  3. Review the decomposition — the Egyptian Fraction Calculator shows each unit fraction chosen at every step, the remaining fraction after subtracting it, and the final expression such as 5/6 = 1/2 + 1/3.

The calculator handles up to 30 steps before reporting that the fraction is too complex. For most classroom and competition fractions, the result is immediate.

Formula & Theory - Egyptian Fraction Calculator

The Egyptian Fraction Calculator applies the Fibonacci-Sylvester greedy algorithm:

Given a/b where a > 0 and b > 0:
1. Find n = ceil(b / a)
2. Subtract 1/n from a/b: new fraction = (a·n − b) / (b·n), then simplify
3. Repeat until the remainder is 0
SymbolMeaning
a/bThe current remaining fraction
nThe denominator of the next unit fraction: n = ⌈b/a⌉
1/nThe unit fraction chosen at each step

Ancient Egyptian mathematicians, particularly in the Rhind Mathematical Papyrus (circa 1650 BCE), used sums of distinct unit fractions to represent all non-integer quantities. The greedy algorithm was later formalized by Fibonacci (1202 CE) and James Joseph Sylvester (1880).

Assumptions and Limits

  • Inputs must be positive. Negative fractions and zero are not supported.
  • The calculator supports improper fractions; the whole-number part is extracted first.
  • Decimal inputs are internally converted to fractions with denominator 10⁹, which is sufficient for most practical values.
  • The algorithm terminates within 30 steps for all common fractions.

Use Cases for Egyptian Fraction Calculator

The Egyptian Fraction Calculator is a practical tool for anyone studying number theory or ancient mathematics. Common uses include:

  • Number theory coursework — explore the properties of unit fractions and understand why every rational number has an Egyptian fraction representation.
  • History of mathematics — reproduce the fraction tables found in the Rhind Papyrus and see how ancient scribes performed arithmetic.
  • Algorithm education — demonstrate the greedy algorithm and its trade-offs, such as producing large denominators for certain inputs.
  • Math competition preparation — Egyptian fraction problems appear in olympiad-level contests; the Egyptian Fraction Calculator lets you verify manual solutions quickly.

Whether you are a student verifying homework, a teacher preparing a demonstration, or simply curious about ancient arithmetic, the Egyptian Fraction Calculator gives you a transparent, step-by-step breakdown every time.

Frequently asked questions about Egyptian Fraction Calculator

What is an Egyptian fraction?

An Egyptian fraction is a representation of a rational number as a sum of distinct unit fractions, each with a numerator of 1. For example, 5/6 = 1/2 + 1/3.

How accurate is the Egyptian Fraction Calculator?

The Egyptian Fraction Calculator uses exact integer arithmetic for fraction inputs, so results are mathematically precise. Decimal inputs are first converted to a fraction with a large denominator, which may introduce minor rounding.

Why does the greedy algorithm sometimes produce large denominators?

The greedy method always picks the largest unit fraction that does not exceed the remainder. While efficient, it does not guarantee the shortest or simplest decomposition — some fractions can have shorter representations found by other methods.

Is my data stored?

No. All calculations happen in your browser; nothing is sent to a server.