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Text Encoding Size Calculator – UTF-8 vs UTF-16

Quick answer

This calculator computes text size in bytes: ASCII uses 1 byte per character in UTF-8, Arabic and other non-Latin scripts about 2.

  • Free UTF-8 and UTF-16 size calculator.

Figures are estimates from this calculator’s standard formula — adjust the inputs in the tool below for your exact number.

How the Text Encoding Calculator Works

bytes = characters × bytes-per-character (UTF-8: 1–4)

Enter the character count and pick the text type: pure ASCII (English code, URLs) averages 1 byte per character in UTF-8, mixed text about 1.5, and non-Latin scripts like Arabic, Hebrew or Cyrillic 2 bytes. UTF-16 uses 2 bytes per character for most scripts — 4 for rare surrogate pairs — so it doubles ASCII storage. The kilobyte output divides UTF-8 bytes by 1,024, the binary unit storage actually bills in.

  1. 1

    Step 1

    Count or paste the character length

  2. 2

    Step 2

    Choose the text type

  3. 3

    Step 3

    Read the UTF-8 byte size

  4. 4

    Step 4

    Compare with UTF-16 and the KB figure

Use Cases

Sizing database text columns

Estimating SMS and API payload sizes

Planning file sizes for subtitle and CSV exports

FAQs

How many bytes is one Arabic character?

2 bytes in UTF-8 and 2 in UTF-16. The 1,001 characters of a typical Arabic paragraph need about 2 KB in UTF-8.

Why is UTF-16 not always smaller?

It fixes 2 bytes per character, so pure-ASCII text doubles compared with UTF-8's 1 byte — UTF-16 wins only on Asian scripts that UTF-8 stores in 3 bytes.

What counts as a character?

Unicode code points as counted by most editors. Emoji count as 2 (a surrogate pair) in UTF-16 and 4 bytes in UTF-8.

Is a kilobyte 1000 or 1024 bytes?

Storage reports binary units: 1 KB = 1,024 bytes, which is what the calculator uses for the KB line.

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