How to Calculate File Size

What is File Size?

Base64 encodes binary data into text using 64 printable ASCII characters, making it safe to transmit in text-based systems like email and URLs. It is not encryption — just encoding.

Formula

Encoded length ≈ (Input length / 3) × 4 | Decoded length ≈ (Encoded length / 4) × 3

n_in: Input bytes (bytes)
n_out: Output bytes (bytes)

Step-by-Step Guide

1Every 3 bytes → 4 Base64 characters
2Characters: A–Z, a–z, 0–9, +, / (64 total)
3= padding makes output a multiple of 4 characters
4Output is ~33% larger than original binary input

Worked Examples

Input

Encode "Man"

Result

"TWFu"

Input

Decode "SGVsbG8="

Result

"Hello"

Frequently Asked Questions

What is Base64 Calc?

Base64 encodes binary data into text using 64 printable ASCII characters, making it safe to transmit in text-based systems like email and URLs. It is not encryption — just encoding

How accurate is the Base64 Calc calculator?

The calculator uses the standard published formula for base64 calc. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

What units does the Base64 Calc calculator use?

This calculator works with inches, percentages. You can enter values in the units shown — the calculator handles all conversions internally.

What formula does the Base64 Calc calculator use?

The core formula is: = padding makes output a multiple of 4 characters. Each step in the calculation is shown so you can verify the result manually.

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