Work out base 64 value instantly with clear inputs, formula shown and shareable results.
Base 64 packs six bits into each digit, using the standard A-Z, a-z, 0-9, plus and slash alphabet. Because 64 = 2⁶, three bytes map exactly onto four base-64 digits, which is why it is used to encode binary as text.
Base 64
value = Σ digitₖ × 64ᵏ, each digit carrying 6 bits
It needs four digits: 61 × 64³ leaves the rest, giving 'D+QA' in the standard alphabet.
It shares the alphabet, but base64 encoding processes byte streams in three-byte groups with padding, rather than converting a single integer.