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Unit converter

Data Storage Converter

Use this free data storage converter to convert file sizes and drive capacities across decimal SI (KB–PB), binary IEC (KiB–PiB), and bits.

Convert file or storage size

Compare base-1000 decimal units used by drive manufacturers with base-1024 binary units used by RAM and operating systems.

Enter file size or disk capacity.
Controls rounding for converted outputs.

Optional download / transfer time estimator

Converted data size

1 Terabyte (TB, decimal) equals

931.322575 GiB
Exact bytes (B)1,000,000,000,000 B
Exact bits (b)8,000,000,000,000 b
Estimated transfer time22h 13m 20s @ 100 Mbps
Decimal vs. binary gap1 TB = 0.9095 TiB (−9.05%)

Decimal (SI 1000), Binary (IEC 1024) & Bit equivalents

    1 Byte = 8 bits. Decimal SI units multiply by 1,000; Binary IEC units (KiB, MiB, GiB, TiB) multiply by 1,024.

    Decimal (KB, MB, GB) vs. Binary (KiB, MiB, GiB)

    Data storage uses two parallel standards that often cause confusion when comparing SSD packaging with Windows File Explorer or Linux memory tools:

    • Decimal SI standard (powers of 1,000): 1 KB = 1,000 B, 1 MB = 1,000,000 B, 1 GB = 109 B, 1 TB = 1012 B. Used by SSD/HDD manufacturers, macOS Finder, iOS, and cloud storage billing.
    • Binary IEC standard (powers of 1,024): 1 KiB = 1,024 B, 1 MiB = 1,048,576 B, 1 GiB = 1,073,741,824 B (230 B), 1 TiB = 240 B. Used for RAM modules and how Windows displays drive sizes (even though Windows labels GiB as "GB").
    • Bits vs. Bytes: 1 Byte (uppercase B) = 8 bits (lowercase b). Internet speeds are sold in megabits per second (Mbps), so a 100 Mbps connection transfers at most 12.5 MB/s before protocol overhead.

    Why a 1 TB drive shows 931 GB on Windows

    • A drive advertised as 1 TB contains 1,000,000,000,000 bytes.
    • Windows divides that byte count by 1,024 × 1,024 × 1,024 (1,073,741,824 bytes per GiB), producing 931.32 GiB.
    • No storage is missing—only the measurement ruler changed! At the terabyte level, binary TiB is ~9.95% larger than decimal TB.

    Frequently asked questions

    How many megabytes (MB) are in 1 gigabyte (GB)?

    In the decimal SI standard (used by storage drives and mobile data plans), 1 GB = 1,000 MB. In binary memory addressing (1 GiB to MiB), 1 GiB = 1,024 MiB.

    Why does my 500 GB SSD only show 465 GB in Windows?

    500 decimal gigabytes equals 500,000,000,000 bytes. Divided by 1,073,741,824 (bytes in 1 binary GiB), Windows reports 465.66 GiB (labeled "GB" in File Explorer).

    What is the difference between MB and Mb?

    Capital B stands for Bytes (8 bits), while lowercase b stands for bits. 1 Megabyte (MB) equals 8 Megabits (Mb). Divide your internet Mbps speed by 8 to get theoretical download speed in MB/s.

    What is a nibble in computing?

    A nibble is 4 bits—half of an 8-bit byte—which corresponds neatly to a single hexadecimal digit (0–F).

    How accurate is the download time estimate?

    It calculates theoretical wire transfer time (total bits ÷ network bits per second). Real-world downloads typically experience 5–10% TCP/IP and TLS overhead, plus server or Wi-Fi limits.

    How big is a petabyte (PB)?

    One decimal petabyte is 1,000 terabytes (1,000,000 gigabytes or 1015 bytes). One binary pebibyte (PiB) is 1,024 tebibytes (250 bytes).

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