How many bytes are in a kilobyte?

In the decimal (metric) system, 1 kilobyte (kB) equals 1,000 bytes. In the binary (IEC) system, 1 kibibyte (KiB) equals 1,024 bytes. Operating systems and hard drive manufacturers often use different systems, which is why a 1 TB drive shows slightly less storage in Windows or macOS.

What is the difference between MB and MiB?

MB stands for megabyte in the decimal system and equals 1,000,000 bytes (10 to the power of 6). MiB stands for mebibyte in the binary IEC system and equals 1,048,576 bytes (2 to the power of 20). The difference is about 4.9 percent. MiB is the precise unit used in computing while MB is common in storage marketing.

In the decimal system, 1 gigabyte (GB) equals 1,000 megabytes (MB). In the binary system, 1 gibibyte (GiB) equals 1,024 mebibytes (MiB). Hard drive manufacturers use 1 GB = 1,000 MB, while operating systems traditionally use the binary definition.

What is the difference between a bit and a byte?

A bit is the smallest unit of digital data and has a value of either 0 or 1. A byte consists of 8 bits and is the standard unit for measuring file sizes and storage capacity. Internet speeds are measured in bits per second (Mbps) while file sizes are measured in bytes (MB, GB).

Why does my 1 TB hard drive show less than 1 TB in Windows?

Hard drive manufacturers measure 1 TB as 1,000,000,000,000 bytes using the decimal system. Windows reports storage using the binary system where 1 TB equals 1,099,511,627,776 bytes. So a 1 TB decimal drive contains about 0.909 binary terabytes, which Windows displays as roughly 931 GB.

How do I convert GB to MB?

To convert gigabytes to megabytes in the decimal system, multiply by 1,000. For example, 5 GB equals 5,000 MB. In the binary system, multiply gibibytes by 1,024 to get mebibytes. For example, 5 GiB equals 5,120 MiB.

What does IEC prefix mean in digital storage?

IEC prefixes are binary unit names standardized by the International Electrotechnical Commission in 1998. They include kibi (Ki, 2 to the 10), mebi (Mi, 2 to the 20), gibi (Gi, 2 to the 30), and tebi (Ti, 2 to the 40). IEC prefixes were created to eliminate confusion between binary and decimal storage units.

In the decimal system, 1 terabyte (TB) equals 1,000 gigabytes (GB). In the binary system, 1 tebibyte (TiB) equals 1,024 gibibytes (GiB). Storage manufacturers use the decimal definition, while operating systems may use either depending on the version.

Digital Storage Unit Converter | Bits Bytes KB MB GB TB

Converter Tool

Digital Storage Unit Converter

Convert between bits, bytes, KB, MB, GB, TB and all binary IEC units instantly. Covers both decimal SI and binary prefix systems with a full step-by-step solution.

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Complete Digital Storage Reference Table

The digital storage reference table below lists every unit supported by this converter, grouped by decimal and binary systems, with the equivalent number of bits and bytes.

Unit	Symbol	System	Bytes	Bits

Binary vs Decimal Storage Units

Digital storage units exist in two parallel systems that use similar names but different scales. Understanding which system applies avoids common confusion about storage sizes.

Decimal (Metric) System

The decimal system uses SI prefixes: kilo (10³), mega (10&sup6;), giga (10&sup9;), tera (10¹²). Hard drive manufacturers, USB drive makers, and internet speed providers use this system. One kilobyte equals exactly 1,000 bytes.

Binary (IEC) System

The binary system uses IEC prefixes: kibi (2¹&sup0; = 1,024), mebi (2²&sup0; = 1,048,576), gibi (2³&sup0; = 1,073,741,824). Operating systems and RAM modules traditionally use this system. One kibibyte equals exactly 1,024 bytes.

Why Your Drive Shows Less Storage Than Advertised

A 1 TB hard drive contains 1,000,000,000,000 bytes (decimal). Windows reports storage in binary units where 1 TB = 1,099,511,627,776 bytes. The same drive therefore appears as approximately 931 GB in Windows Explorer, which is 931 GiB expressed without the IEC label.

Percent Difference at Each Scale

Binary Unit	Decimal Equivalent	Difference
1 KiB (1,024 B)	1.024 kB	2.4%
1 MiB (1,048,576 B)	1.049 MB	4.9%
1 GiB (1,073,741,824 B)	1.074 GB	7.4%
1 TiB (1,099,511,627,776 B)	1.100 TB	10.0%
1 PiB	1.126 PB	12.6%
1 EiB	1.153 EB	15.3%

Common Digital Storage Conversions

Common digital storage conversions are listed below for quick reference when working with file sizes, internet speeds, or device specifications.

1 byte = 8 bits
1 kilobyte (kB) = 1,000 bytes = 8,000 bits
1 megabyte (MB) = 1,000 kB = 1,000,000 bytes
1 gigabyte (GB) = 1,000 MB = 1,000,000,000 bytes
1 terabyte (TB) = 1,000 GB = 1,000,000,000,000 bytes
1 kibibyte (KiB) = 1,024 bytes
1 mebibyte (MiB) = 1,024 KiB = 1,048,576 bytes
1 gibibyte (GiB) = 1,024 MiB = 1,073,741,824 bytes

Internet Speed vs File Size

Internet speeds are measured in megabits per second (Mbps) while file sizes use megabytes (MB). To find download time, divide the file size in megabytes by the speed in megabytes per second. Divide Mbps by 8 to get MB per second.

Frequently Asked Questions

In the decimal (metric) system, 1 kilobyte (kB) equals 1,000 bytes. In the binary (IEC) system, 1 kibibyte (KiB) equals 1,024 bytes. Operating systems and hard drive manufacturers often use different systems, which is why a 1 TB drive shows slightly less storage in Windows or macOS.
MB stands for megabyte in the decimal system and equals 1,000,000 bytes (10 to the power of 6). MiB stands for mebibyte in the binary IEC system and equals 1,048,576 bytes (2 to the power of 20). The difference is about 4.9 percent. MiB is the precise unit used in computing while MB is common in storage marketing.
In the decimal system, 1 gigabyte (GB) equals 1,000 megabytes (MB). In the binary system, 1 gibibyte (GiB) equals 1,024 mebibytes (MiB). Hard drive manufacturers use 1 GB = 1,000 MB, while operating systems traditionally use the binary definition.
A bit is the smallest unit of digital data and has a value of either 0 or 1. A byte consists of 8 bits and is the standard unit for measuring file sizes and storage capacity. Internet speeds are measured in bits per second (Mbps) while file sizes are measured in bytes (MB, GB).
Hard drive manufacturers measure 1 TB as 1,000,000,000,000 bytes using the decimal system. Windows reports storage using the binary system where 1 TB equals 1,099,511,627,776 bytes. So a 1 TB decimal drive contains about 0.909 binary terabytes, which Windows displays as roughly 931 GB.
To convert gigabytes to megabytes in the decimal system, multiply by 1,000. For example, 5 GB equals 5,000 MB. In the binary system, multiply gibibytes by 1,024 to get mebibytes. For example, 5 GiB equals 5,120 MiB.
IEC prefixes are binary unit names standardized by the International Electrotechnical Commission in 1998. They include kibi (Ki, 2 to the 10), mebi (Mi, 2 to the 20), gibi (Gi, 2 to the 30), and tebi (Ti, 2 to the 40). IEC prefixes were created to eliminate confusion between binary and decimal storage units.
In the decimal system, 1 terabyte (TB) equals 1,000 gigabytes (GB). In the binary system, 1 tebibyte (TiB) equals 1,024 gibibytes (GiB). Storage manufacturers use the decimal definition, while operating systems may use either depending on the version.