Calculate the size increase from Base64 encoding binary data.
Base64 turns every three bytes into four characters, a fixed 33 per cent increase before line breaks. That overhead is why inlining large images as data URIs makes pages heavier rather than lighter. The encoding exists to move binary safely through text channels, so the 33 per cent cost is a transport necessity rather than a compression choice.
Base64 Size
Encoded size = ⌈bytes ÷ 3⌉ × 4, plus one byte per wrapped line
Encoded size = ⌈bytes ÷ 3⌉ × 4, plus one byte per wrapped line Base64 turns every three bytes into four characters, a fixed 33 per cent increase before line breaks. That overhead is why inlining large images as data URIs makes pages heavier rather than lighter.
The encoding exists to move binary safely through text channels, so the 33 per cent cost is a transport necessity rather than a compression choice.
This calculator takes 2 inputs: Original size, Line wrap width, zero for none. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.