1 GB (gigabyte) = 1,000 MB (SI definition). In binary, 1 GiB (gibibyte) = 1,024 MiB. Hard drive manufacturers use SI; operating systems historically used binary, which is why drives appear smaller than advertised.

What is the difference between GB and GiB?

1 GB = 1,000,000,000 bytes (SI). 1 GiB = 1,073,741,824 bytes (2³⁰ bytes). GiB is about 7.4% larger than GB.

How many bytes are in a terabyte?

1 TB = 1,000,000,000,000 bytes (10¹²). 1 TiB = 1,099,511,627,776 bytes (2⁴⁰).

Data Storage Converter

How to Use the Data Storage Converter

Enter the storage value in the Value field and select the unit you are converting from. All equivalents update instantly.

Data Storage Units Explained

SI units (decimal, powers of 1000)

Bit — the smallest unit: 0 or 1.
Byte (B) — 8 bits. One character of text.
Kilobyte (KB) — 1,000 bytes. Small text files.
Megabyte (MB) — 1,000,000 bytes. A photo, a song.
Gigabyte (GB) — 1,000,000,000 bytes. A full movie (HD ≈ 4–8 GB).
Terabyte (TB) — 1,000,000,000,000 bytes. Hard drive capacity.
Petabyte (PB) — 10¹⁵ bytes. Large data centers.

IEC binary units (powers of 1024)

Kibibyte (KiB) — 1,024 bytes (2¹⁰).
Mebibyte (MiB) — 1,048,576 bytes (2²⁰).
Gibibyte (GiB) — 1,073,741,824 bytes (2³⁰).
Tebibyte (TiB) — 1,099,511,627,776 bytes (2⁴⁰).

Why Drives Appear Smaller Than Advertised

Drive manufacturers use SI (1 TB = 10¹² bytes). Operating systems traditionally counted in binary (GiB). A 1 TB drive shows as 931 GiB in Windows because 10¹² ÷ 2³⁰ ≈ 931.

Worked Examples

Photo: 12 MP JPEG ≈ 4 MB to bits

4 × 1,000,000 × 8 = 32,000,000 bits (32 Mbit).

SSD: 500 GB to GiB

500,000,000,000 ÷ 1,073,741,824 = 465.7 GiB. This is why a "500 GB" SSD shows as ~466 GB in Windows.

Movie: 4K Blu-ray ≈ 100 GB to TiB

100,000,000,000 ÷ 1,099,511,627,776 = 0.091 TiB.

RAM: 16 GiB to GB

16 × 1,073,741,824 = 17,179,869,184 bytes = 17.18 GB.

Frequently Asked Questions

How many bytes in a gigabyte?

1 GB (SI) = 1,000,000,000 bytes. 1 GiB (binary) = 1,073,741,824 bytes.

Why does Windows show less storage than the drive label?

Drive manufacturers use SI units (1 TB = 10¹² bytes). Windows traditionally displayed storage in binary GiB but labeled them GB. A 1 TB drive = 931 GiB, which Windows showed as "931 GB" — about 7% less than advertised.

What is a petabyte?

1 PB = 1,000 TB = 10¹⁵ bytes. To store 1 PB of data you'd need about 1,000 one-terabyte hard drives. Major internet companies store hundreds of petabytes.