Data Storage Unit Converter
Online data storage unit conversion tool, supports fast conversion between bit, byte, KB, MB, GB, TB and binary units
What is Data Storage Unit Conversion?
The Data Storage Converter converts values between bits, bytes, KB, MB, GB, TB, PB, EB, and binary units such as KiB, MiB, GiB, and TiB. Its value comes from a common mismatch: hardware vendors, operating systems, networks, and cloud providers do not always use the same unit convention, with decimal units based on 1000 and binary units based on 1024. That difference explains why a drive, memory figure, transfer quota, or backup estimate may look different across tools. The converter helps with capacity planning, upload limits, bandwidth math, documentation, and cost estimates. It still does not account for filesystem overhead, compression, redundancy, or reserved space.
How to Use
How to use
- Enter the value you want to convert
- Select source unit (from) and target unit (to)
- Click 'Convert' to see detailed results
- Click 'Related Conversions' to explore other unit combinations
Decimal vs Binary
- Check whether the source uses decimal units (KB, MB, GB) or binary units (KiB, MiB, GiB); storage vendors and operating systems often differ.
- For billing, quotas, or transfer limits, keep the unit label with the number so the value is not misread later.
Use Cases
Technical Principle
Data storage uses two parallel prefix systems with different numeric bases. The decimal (SI) system uses powers of 10: 1 KB = 10^3 B, 1 MB = 10^6 B, 1 GB = 10^9 B, scaling up to 1 YB = 10^24 B (yotta, added in CGPM 1991; ronna 10^27 and quetta 10^30 added in 2022). The binary system, formalized in IEC 80000-13:2008 (originally IEC 60027-2:1999), uses powers of 2 and writes them with an explicit "i" infix: 1 KiB = 2^10 B = 1,024 B, 1 MiB = 2^20 B, 1 GiB = 2^30 B, 1 TiB = 2^40 B, 1 YiB = 2^80 B. The IEC names (kibi, mebi, gibi, tebi, pebi, exbi, zebi, yobi) exist precisely to remove the historical ambiguity where 1 KB meant 1,000 B in network spec sheets but 1,024 B in operating-system file listings. Vendor and OS choices follow industry convention rather than user preference. Hard-drive, SSD, and cloud-storage vendors use decimal units because the drive's raw capacity in sectors maps cleanly to 10^n powers (a 1 TB drive contains 1,953,525,168 LBAs of 512 B = 10^12 B). Windows Explorer historically displays binary values but labels them with decimal prefixes ("931 GB" for what is actually 931 GiB), which is the most common source of the "my drive is smaller than advertised" complaint; macOS switched to true decimal display in 10.6 Snow Leopard (2009), and most Linux file managers follow the same SI convention. Network throughput is reported in bits per second (1 Gbps = 10^9 bit/s = 125 MB/s decimal theoretical max), while file sizes are in bytes, so a 1 GB file on a perfectly clean gigabit link transfers in 8 s + TCP/IP overhead. Internally the converter normalizes every input to bits (the smallest atom: 1 byte = 8 bits per IEC 80000-13 and the historical PDP-10/IBM 360 convention) and applies a single multiplication by the target factor, avoiding the precision drift that accumulates when long chains like KB → MB → GB → TiB are evaluated separately. IEEE 754 doubles give ~15-17 significant decimal digits, which covers conversions up to roughly 9 PB exactly and remains accurate to the kilobyte at exabyte scale. For values above 2^53 bits (about 1 PiB) the tool falls back to BigInt arithmetic where exact byte counts matter, such as block-storage allocation reports. Filesystem overhead, RAID parity, and SSD spare area are out of scope for unit conversion — a freshly formatted 1 TB NTFS volume reports about 931 GiB before MFT and reserved space, and ZFS with a copies=2 setting halves the user-visible capacity again.
- Decimal (SI) prefixes: K=10^3, M=10^6, G=10^9, T=10^12, P=10^15, E=10^18, Z=10^21, Y=10^24 (CGPM 1991); R=10^27, Q=10^30 added in CGPM 2022
- Binary (IEC 80000-13:2008) prefixes: Ki=2^10=1,024, Mi=2^20, Gi=2^30, Ti=2^40, Pi=2^50, Ei=2^60, Zi=2^70, Yi=2^80 — explicit "i" infix removes the legacy KB ambiguity
- Decimal-to-binary gap: 1 GB = 0.9313 GiB (7.4 % smaller), 1 TB = 0.9095 TiB (~9.1 % smaller), 1 PB = 0.8882 PiB; this is why a 1 TB drive shows ~931 GB in Windows
- Bit vs byte: 1 B = 8 bit (IEC 80000-13); network speeds use lowercase b (1 Gbps = 125 MB/s decimal theoretical, ~112 MiB/s after TCP/IP overhead)
- OS conventions: Windows displays binary values with decimal labels ("GB" meaning GiB), macOS 10.6+ uses true SI decimal, most Linux file managers follow SI; iOS and Android report storage in decimal GB
- Endianness and word size are separate concerns: big-endian (network byte order, RFC 1700) vs little-endian (x86, ARM default), and word widths of 8/16/32/64 bits affect memory layout but not the unit conversion
- Precision: IEEE 754 doubles handle ~9 PB exactly; the converter normalizes to bits internally and switches to BigInt above 2^53 bits to keep exact byte counts for storage allocation reports
Examples
Decimal GB to MB and bytes
1 GB = 1,000 MB = 1,000,000 KB = 10⁹ bytesBinary GiB to MiB and bytes
1 GiB = 1,024 MiB = 1,048,576 KiB = 2³⁰ bytes ≈ 1.0737 × 10⁹ bytesSI vs. IEC mismatch (why a 1 TB drive shows 931 GB)
1 TB (decimal) = 10¹² bytes ≈ 931.32 GiB; 1 TiB = 2⁴⁰ bytes ≈ 1.0995 TB — about a 7-9% gapBandwidth: bits per second vs. bytes per second
1 Gbps = 1,000 Mbps = 125 MB/s; downloading a 1 GB file on a clean 1 Gbps link ≈ 8 secondsMedia file sizes (everyday reference)
4K H.265 video ≈ 375 MB per minute ≈ 22.5 GB per hour; a 3-minute MP3 (320 kbps) ≈ 7.3 MBCloud and backup capacity
100 GB plan = 10¹¹ bytes ≈ 93.13 GiB visible in the OS; a 16 GB phone shows ≈ 14.9 GiB before the system partitionFAQ
Is 1 KB equal to 1000 bytes or 1024 bytes?
Both definitions exist. SI uses 1 KB = 1000 bytes; binary (IEC) uses 1 KiB = 1024 bytes. Operating systems and hard-drive vendors disagree: Windows reports file sizes in 1024-based units but labels them 'KB', while disk capacity is advertised in 1000-based units. The page exposes both columns so you can compare.
How big is one terabyte really?
1 TB = 1,000,000,000,000 bytes (SI). 1 TiB = 2^40 = 1,099,511,627,776 bytes. A '1 TB' hard drive shows about 931 GiB inside Windows because of this difference, not because of capacity loss to formatting.
Why do email and image attachments often look smaller than my disk shows?
Email attachments grow about 33% during MIME Base64 encoding; some clients display the original file size, others display the over-the-wire size. Browser developer tools, by contrast, often show the gzipped transfer size. None of these are 'wrong' - they measure different things.
What's a bit, a byte, a nibble, a word?
Bit (b) is one binary digit. Byte (B) is 8 bits. Nibble is 4 bits (one hex digit). 'Word' depends on the architecture - 16, 32, or 64 bits. Network bandwidth is conventionally measured in bits per second (Mbps), file size in bytes per second (MB/s) - 1 MB/s = 8 Mbps.
Can I convert bandwidth values?
Yes - the page treats Mbps and MBps as separate units (one with 'b' for bits, one with 'B' for bytes). 100 Mbps = 12.5 MB/s. Always check the case of the 'B' character; ISP marketing nearly always uses bits per second.
What's the largest unit listed?
Yottabyte (YB, 10^24 B) for SI and yobibyte (YiB, 2^80 B) for binary. Petabyte and exabyte are commonly seen in cloud storage; zettabyte and yottabyte rarely appear outside global-traffic statistics.
Are all conversions exact?
Within unit families (KB → MB, KiB → MiB) yes. Across families (KB → KiB) the conversion factor is 1000/1024 and produces a non-integer ratio; the page rounds to a sensible precision but the underlying number is irrational in either base.