Binary Numbers & Logic

Binary Fraction Converter

Convert fractional values between base two and finite decimal input.

Binary Numbers & Logic

Enter binary or code values

Deterministic local calculation with explicit word sizes and conventions
  1. 1EnterProvide the known values
  2. 2CalculateResults update automatically
  3. 3VerifyReview the details and units
Try an example

Prefixes 0b, 0o, and 0x are accepted where a field says “integer”. Underscores and visual spacing are ignored where appropriate. Your values stay in this browser.

Binary result

Enter valid values to see the result.

Your entries are calculated in this browser and are not submitted to 365CALCS.COM.

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Understand the subject

How do binary fractions work?

Digits right of the binary point represent halves, quarters, eighths, and further powers of two.

Use it to translate finite binary fractions and their decimal values.

The rule

Read the representation exactly

See the structure

What the bits are doing

Worked interpretation

Read the result in context

0.101₂=1/2+0/4+1/8

Interpret with care

Important boundary

Many decimal fractions repeat forever in binary.

For a small base-two example, use the Binary Calculator.

Quick guide

How to use this calculator

  1. Choose the direction, operation, representation, or parity convention when one is provided.
  2. Enter the labelled values and an explicit word size, base, polynomial, or encoding option where required.
  3. Read the primary result together with its alternate representations and stated convention.

Calculation method

Apply the declared binary rule

Digits after the binary radix point have weights 2⁻¹, 2⁻², and so on.

The calculator validates every digit against its numeral base, keeps integer and bitwise work exact with arbitrary-precision integers, and limits fixed-width operations to the selected word.

Worked example

Worked binary example

101.101₂ = 5.625₁₀.

Digits after the binary radix point have weights 2⁻¹, 2⁻², and so on.

Supported inputs

Precision and limits

Input interpretation

Binary-only fields accept 0 and 1. General integer fields accept decimal plus 0b, 0o, or 0x prefixes. Base conversion supports bases 2 through 36.

Word size and output

Most fixed-width tools support 1–256 bits. Results expose signedness, truncation, parity, or encoding conventions whenever those choices change the meaning.

Local privacy

Calculation runs in the browser. Entered text, bit patterns, code words, and numeric values are not sent to analytics or third parties.

Calculator-specific rule

Repeating binary expansions use parentheses when a cycle is detected; long previews are truncated after 64 fractional bits.