Bits to Bytes Converter

Last updated: April 5, 2026

The Bits to Bytes Converter converts between all digital storage units — bits, bytes, kilobytes, megabytes, gigabytes, terabytes — in both SI base-10 and IEC binary standards. Eliminates the confusion between storage advertised in gigabytes and what your operating system actually reports.

Calculator

Bitsb

Conversion Base

Results

Bytes

Kilobytes

0.000977

Megabytes

0.000001

Gigabytes

9.313226e-10

Remaining Bits After Whole Bytes

Whole Bytes

Results

Bytes

Kilobytes

0.000977

Megabytes

0.000001

Gigabytes

9.313226e-10

Remaining Bits After Whole Bytes

Whole Bytes

Your 1 TB hard drive contains 931 GB according to your computer. Your 100 Mbps internet connection tests at 12.5 MB/s download speed. Your 8 GB phone holds 7.45 GiB of actual storage. These discrepancies are not errors — they result from the coexistence of two incompatible unit systems that the storage and networking industries have used simultaneously for decades. The bits to bytes converter converts between all units in both systems with complete transparency about which system is being used.

The Two Unit Systems: SI vs. Binary (IEC)

The fundamental confusion:

SI (metric) prefixes — used by storage manufacturers: 1 kilobyte (KB) = 1,000 bytes; 1 megabyte (MB) = 1,000,000 bytes; 1 gigabyte (GB) = 1,000,000,000 bytes; 1 terabyte (TB) = 10¹² bytes
Binary (IEC) prefixes — used by operating systems: 1 kibibyte (KiB) = 1,024 bytes; 1 mebibyte (MiB) = 1,048,576 bytes; 1 gibibyte (GiB) = 1,073,741,824 bytes; 1 tebibyte (TiB) = 2⁴⁰ bytes

Storage manufacturers use SI because it makes drives sound bigger. Operating systems use binary because memory addressing naturally works in powers of 2. The resulting gap: a "1 TB" drive contains 1,000,000,000,000 bytes = 931.32 GiB (binary gigabytes). Use this online calculator for any unit conversion in either system. The bandwidth calculator handles data rate conversions for network planning.

Bits vs. Bytes: The Critical Networking Distinction

The most persistent source of data unit confusion: networking speeds are measured in bits per second; file sizes in bytes. The conversion:

Download time = File size (bytes) × 8 / Connection speed (bits per second)

For a 100 Mbps (megabits per second) connection downloading a 1 GB (gigabyte) file: File size in megabits = 1,000 × 8 = 8,000 Mb; Download time = 8,000 Mb / 100 Mbps = 80 seconds. But if the ISP means 100 Mbps and the file is 1 GiB (binary): 1 GiB = 8,589,934,592 bits; time = 8,589,934,592 / 100,000,000 = 85.9 seconds. The capital B vs. lowercase b convention (MB = megabytes, Mb = megabits) is the standard notation, though it is frequently ignored in casual usage.

Unit Conversion Table: Powers of 2 vs. Powers of 10

Reference for SI vs. binary prefixes:

1 KB (SI) = 1,000 bytes; 1 KiB (IEC) = 1,024 bytes — 2.4% difference
1 MB (SI) = 1,000,000 bytes; 1 MiB (IEC) = 1,048,576 bytes — 4.9% difference
1 GB (SI) = 1,000,000,000 bytes; 1 GiB (IEC) = 1,073,741,824 bytes — 7.4% difference
1 TB (SI) = 10¹² bytes; 1 TiB (IEC) = 1,099,511,627,776 bytes — 9.95% difference

The gap grows at each level — at the TB scale, the 9.95% difference is practically significant: a "1 TB" drive stores approximately 931 GiB (Windows-reported value). The data storage converters cover all digital unit conversions.

Historical Context: Why Two Systems Exist

The ambiguity dates to the 1960s–70s, when both computer scientists (working with binary powers of 2) and manufacturers (working with decimal prefixes from SI) began using the same "kilo/mega/giga" prefixes to mean different things. The International Electrotechnical Commission (IEC) introduced the binary prefixes (kibi-, mebi-, gibi-, tebi-) in 1998 to resolve the ambiguity, but adoption has been slow: Windows and Linux now use IEC binary prefixes; macOS switched to SI decimal prefixes in OS X 10.6 (Snow Leopard) in 2009. The result is that two different operating systems reporting different sizes for the same file — both correctly, just using different unit conventions.

Visual Analysis

How It Works

Enter a value and select the source unit (bits, bytes, KB, MB, GB, TB, Kbps, Mbps, etc.) and the target unit. The calculator applies the correct conversion factor: for SI units, multiplies or divides by powers of 1,000; for IEC binary units (KiB, MiB, GiB, TiB), uses powers of 1,024. Select SI or IEC mode to determine which system is used for ambiguous prefixes (K, M, G, T).

Understanding Your Results

Practical examples: a single ASCII character is 8 bits (1 byte), a Unicode emoji may be 32 bits (4 bytes), an IPv4 address is 32 bits (4 bytes), a MAC address is 48 bits (6 bytes), an IPv6 address is 128 bits (16 bytes). Internet speeds: 100 Mbps = 12.5 MB/s, 1 Gbps = 125 MB/s.

Worked Examples

One Byte

Inputs

bits8

Results

bytes1

kb0.000977

8 bits = 1 byte

Internet Speed

Inputs

bits100000000

Results

bytes12500000

kb12207.03125

100 Mbps = 12.5 MB/s ≈ 12,207 KB/s

Frequently Asked Questions

Hard drive manufacturers measure 1 TB as 1,000,000,000,000 bytes (powers of 10 — SI metric system). Windows, Linux, and most operating systems historically report storage in binary units: 1 GB = 1,073,741,824 bytes (2³⁰). Converting: 1,000,000,000,000 bytes ÷ 1,073,741,824 bytes/GB = 931.32 GB. There is no missing storage — the manufacturer and operating system are both correct, just using different unit definitions. macOS resolved this differently in 2009: it switched to using SI units like the manufacturers, so a 1 TB drive appears as 1.0 TB in macOS. The IEC introduced standardized binary prefixes (gibibyte, GiB) to distinguish the two, but adoption in OS interfaces has been inconsistent.

Mbps = megabits per second (network speed); MB/s = megabytes per second (file transfer speed). Since 1 byte = 8 bits: MB/s = Mbps ÷ 8. A 100 Mbps internet connection transfers data at 100 ÷ 8 = 12.5 MB/s maximum. A 1 Gbps (gigabit) connection transfers at 1,000 ÷ 8 = 125 MB/s. This distinction is why internet service providers advertise speeds in megabits while download managers show megabytes — both are measuring the same physical data transfer, just in different units. Common confusion: people expect to download at 100 MB/s on a 100 Mbps plan and feel cheated when they see 12 MB/s. The correct expectation is 12.5 MB/s, and protocol overhead typically reduces actual throughput to 8–11 MB/s.

In SI (base-10, used by hard drive manufacturers): 1 gigabyte (GB) = 1,000,000,000 bytes = 10⁹ bytes. In IEC binary (used by operating systems historically): 1 gibibyte (GiB) = 1,073,741,824 bytes = 2³⁰ bytes. The difference is about 7.4%. For RAM and flash storage, binary (powers of 2) is the natural unit because memory addressing uses binary. RAM marketed as '8 GB' is almost always exactly 8 GiB (8 × 1,073,741,824 = 8,589,934,592 bytes), making memory one area where manufacturers use binary despite the SI convention for HDDs. This inconsistency exists because memory capacity must be an exact power of 2 for addressing to work correctly.

The IEC (International Electrotechnical Commission) introduced standardized binary prefixes in 1998 to replace the ambiguous kilo/mega/giga when used to mean powers of 2: kibibyte (KiB) = 2¹⁰ = 1,024 bytes; mebibyte (MiB) = 2²⁰ = 1,048,576 bytes; gibibyte (GiB) = 2³⁰ = 1,073,741,824 bytes; tebibyte (TiB) = 2⁴⁰ = 1,099,511,627,776 bytes; pebibyte (PiB) = 2⁵⁰ bytes. The names combine the SI prefix with 'bi' for binary: kilo + bi = kibi, mega + bi = mebi, giga + bi = gibi. These precise terms eliminate ambiguity in technical specifications. Linux (since 2007), GNU tools, and scientific computing use these consistently; Windows and macOS are inconsistent in their IEC prefix usage in UI displays.

Terabyte (TB, SI): 10¹² = 1,000,000,000,000 bytes. Tebibyte (TiB, IEC binary): 2⁴⁰ = 1,099,511,627,776 bytes. Difference: 1 TiB is about 9.95% larger than 1 TB. In practical terms: a storage device marketed as 10 TB contains 10,000,000,000,000 bytes, which equals 9.09 TiB or 9,313 GiB. At the petabyte scale: 1 PB (SI) = 10¹⁵ bytes; 1 PiB (IEC) = 2⁵⁰ bytes — the difference grows to 12.6%. Data center storage is often quoted in petabytes or exabytes, making the choice of SI vs. binary units significant for capacity planning. Scientific computing and cloud storage providers are increasingly explicit about which system they use in service agreements.

Convert both values to the same units first. Download time (seconds) = File size (bits) ÷ Connection speed (bits per second). Practical formula: time (seconds) = File size (MB) × 8 ÷ Speed (Mbps). For a 4 GB movie file on a 50 Mbps connection: 4,000 MB × 8 ÷ 50 Mbps = 640 seconds ≈ 10.7 minutes. For a 4 GiB file (operating system representation): 4 × 1,024 × 8 ÷ 50 = 655 seconds ≈ 10.9 minutes. In practice, reduce theoretical maximum by 10–30% for protocol overhead, network congestion, and server-side rate limiting — a 50 Mbps connection may achieve 8–10 MB/s effective download speed on most consumer internet connections.

Sources & Methodology

International Electrotechnical Commission IEC 80000-13 (2008). Quantities and Units for Information Science and Technology. IEEE 1541-2002. Prefixes for Binary Multiples. NIST SP 811 (2008).

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How It Works

Frequently Asked Questions