Convert decimal digit strings to or from 8421 binary-coded decimal.
Binary Numbers & Logic
Enter binary or code values
Deterministic local calculation with explicit word sizes and conventions
1EnterProvide the known values
2CalculateResults update automatically
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.
Choose the direction, operation, representation, or parity convention when one is provided.
Enter the labelled values and an explicit word size, base, polynomial, or encoding option where required.
Read the primary result together with its alternate representations and stated convention.
Calculation method
Apply the declared binary rule
Each decimal digit is encoded independently in four binary bits.
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
59 becomes 0101 1001 in BCD.
Each decimal digit is encoded independently in four binary bits.
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.
