CalcaTools

Bits Calculator

Converts data sizes between bits, bytes and every decimal and binary multiple from kilobits to terabytes.

Last updated: June 2026 · Free · No sign-up required

Results

Enter values above and click Calculate to see your result instantly.

What is the Bits Calculator?

A data-size converter that moves between bits, bytes and every common multiple — kilobits, kilobytes, MB, GB, TB and the binary units KiB, MiB and GiB. It also explains the classic mystery: a “1 TB” drive is 931 GiB, because drive makers count powers of 1,000 while your OS counts powers of 1,024.

How to use the Bits Calculator

  1. Enter the data size.
  2. Pick its unit (bits, bytes, KB, MB, GB, TB, KiB, MiB, GiB).
  3. Read the value in every other unit instantly.

Quick reference

UnitEquals
1 byte8 bits
1 KB (kilobyte)1,000 bytes
1 KiB (kibibyte)1,024 bytes
1 MB1,000,000 bytes
1 GB8,000,000,000 bits
1 TB931.32 GiB

Interpretation guide

ContextWhich unit is meant
Internet speed (100 Mbps)Megabits per second — divide by 8 for MB/s
Drive capacity on the boxDecimal GB/TB (powers of 1,000)
Capacity Windows reportsBinary GiB shown as 'GB' (powers of 1,024)
RAMTrue binary — 16 GB RAM is 16 GiB

Formula & methodology

Formula: bits = value × unit factor; 1 byte = 8 bits; KB/MB/GB use ×1,000 steps, KiB/MiB/GiB use ×1,024 steps

  1. The input is converted to bits (1 byte = 8 bits; decimal prefixes step ×1,000, binary prefixes ×1,024).
  2. The bit total is divided by each target unit's factor.

Worked example: a '1 TB' drive is 8 × 10¹² bits = 10¹² bytes, which is 10¹² ÷ 1,024³ = 931.32 GiB — that's the whole mystery of the 'missing' 69 GB. And a 100 Mbps connection moves 100 ÷ 8 = 12.5 MB/s at best.

Frequently asked questions

How many bits are in a byte?
8 bits make 1 byte. A kilobyte is 8,000 bits, a megabyte 8 million, and a gigabyte 8 billion bits.
Why does my 1 TB drive only show 931 GB?
Drive makers count decimal terabytes (10¹² bytes); Windows reports binary gibibytes (1,024³ bytes) while labeling them 'GB'. 10¹² ÷ 1,024³ = 931.32 — no space is actually missing.
What is the difference between Mbps and MB/s?
Mbps is megabits per second, MB/s is megabytes per second — 8 times larger. A 100 Mbps internet plan tops out at 12.5 MB/s of actual file transfer.
What is a kibibyte (KiB)?
The unambiguous binary unit: 1 KiB = 1,024 bytes, 1 MiB = 1,024², 1 GiB = 1,024³. The 'i' names were standardized so 'kilo' could mean exactly 1,000 like everywhere else in science.
How many bytes is a gigabyte?
A decimal gigabyte is exactly 1,000,000,000 bytes. The binary gibibyte is 1,073,741,824 bytes — about 7.4% bigger, which is why the two systems drift further apart at TB scale.

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