Data Storage Converter
Compare decimal (GB) and binary (GiB) storage units. Shows both so you can match manufacturer specs with OS-reported capacity.
Data Storage Converter
Enter a data size and select its unit β all other units update instantly.
Quick References
How to Convert Between Bytes, KB, MB, GB, and TB
Your laptop has a 512 GB SSD. You want to know how many GiB that actually is. Type 512, select GB, and see that it equals 476.8 GiB. The SSD manufacturer used decimal (SI) where 1 GB = 1,000,000,000 bytes, but your operating system uses binary (IEC) where 1 GiB = 1,073,741,824 bytes. The difference is about 7%, which is why a "512 GB" drive shows as 476.8 GiB in Windows.
The converter handles 16 units: bit, kilobit, megabit, gigabit, terabit (for network speeds), byte, KB, MB, GB, TB, PB (decimal/SI), and KiB, MiB, GiB, TiB, PiB (binary/IEC). A network engineer calculating download time for a 4.7 GB DVD image at 50 Mbps gets 37.6 Gb, which takes about 752 seconds (12.5 minutes). The quick-reference row shows real objects: plain text page at 2 KB, MP3 song at 4 MB, HD movie at 4.5 GB, Blu-ray disc at 50 GB.
Why your hard drive appears smaller than advertised
A 1 TB hard drive stores 1,000,000,000,000 bytes (decimal). Your OS divides by 1,073,741,824 (binary) and reports 931.3 GiB. This is not a defect or missing space. Both numbers describe the same physical storage. The discrepancy compounds at larger scales: 4 TB = 3,637.9 GiB. Cloud providers charge for decimal GB, but your VM reports binary GiB. Always convert before provisioning.
Your internet plan is 100 Mbps (megabits per second). To convert to megabytes per second: divide by 8. You get 12.5 MB/s. A 4.7 GB file = 37.6 Gb. At 100 Mbps, the download takes 376 seconds (about 6.3 minutes). If someone advertises "12.5 MB/s" and you think they mean megabits, you would overestimate your speed by 8x.
A standard DVD holds 4.7 GB (decimal). In binary, that is 4.38 GiB. The disc contains exactly 4,700,000,000 bytes. Your OS divides by 1,073,741,824 and reports 4.38 GiB. The same 4.7 GB equals 37.6 Gb (gigabits) because 1 byte = 8 bits. This converter shows all three values simultaneously so you can verify which unit someone is quoting.
Related tools
How the Data Storage Converter Handles Bytes, KB, and GiB
All conversions pass through a single base unit: bytes. When you enter 1 TB, the tool multiplies by 1,000,000,000,000 (10^12) to get bytes, then divides by each target unit's factor. For GiB, it divides by 1,073,741,824 (2^30) and gets 931.3 GiB. For bits, it multiplies by 8 and gets 8,000,000,000,000 bits.
Two prefix systems that cause confusion
Decimal (SI) prefixes use powers of 1000: 1 KB = 1,000 bytes, 1 MB = 1,000,000 bytes, 1 GB = 1,000,000,000 bytes. Binary (IEC) prefixes use powers of 1024: 1 KiB = 1,024 bytes, 1 MiB = 1,048,576 bytes, 1 GiB = 1,073,741,824 bytes. Storage manufacturers use decimal because the numbers look bigger. Operating systems use binary because memory is addressed in powers of 2. This is why a 1 TB drive shows as 931.3 GiB.
The difference compounds at each tier. At KB/KiB, the gap is 2.4%. At MB/MiB, it is 4.9%. At GB/GiB, it is 7.4%. At TB/TiB, it is 9.1%. At PB/PiB, it reaches 11.3%. The ratio at each tier is 1000/1024 = 0.9765625, which compounds as you move up. This is why the gap between a 1 TB drive and its GiB equivalent is larger than the gap between a 1 KB file and its KiB equivalent.
Bits vs bytes for network calculations
Network speeds use bits: 100 Mbps = 100 megabits per second. File sizes use bytes: 1 GB = 1,000,000,000 bytes. To convert between them, divide bits by 8 to get bytes. A 100 Mbps connection transfers 12.5 MB/s. A 1 Gbps connection transfers 125 MB/s. The converter handles bit-level units (bit, kb, Mb, Gb, Tb) alongside byte-level units, so you can convert a 4.7 GB DVD image to gigabits (37.6 Gb) and calculate download time at your connection speed.
All conversion factors are exact by definition: 1 KB = 10^3 bytes, 1 KiB = 2^10 bytes = 1,024 bytes, 1 MB = 10^6 bytes, 1 MiB = 2^20 bytes = 1,048,576 bytes. The factors are stored as JavaScript numbers, which provide 15-17 significant digits of precision. This is far more precision than any real-world storage measurement, which typically has uncertainty of 1-5% depending on formatting, partitioning, and filesystem overhead.
Frequently Asked Questions
Why does my 1 TB hard drive show as 931 GiB?
The drive stores 1,000,000,000,000 bytes (decimal). Your OS divides by 1,073,741,824 (2^30) and reports 931.3 GiB. Both numbers describe the same physical storage. The difference comes from manufacturers using powers of 1000 while operating systems use powers of 1024. This is not a defect or missing space.
How do I convert MB to MiB?
Multiply by 0.95367431640625 (which is 1,000,000 / 1,048,576). So 100 MB = 95.37 MiB. Or divide MB by 1.048576 to get MiB. The difference grows at larger scales: 1 TB = 931.3 GiB, while 1 PB = 931.3 TiB. The ratio is always the same because it compounds at each power of 1024.
What is the difference between Mbps and MBps?
Mbps = megabits per second. MBps = megabytes per second. Since 1 byte = 8 bits, divide Mbps by 8 to get MBps. A 100 Mbps connection = 12.5 MBps. A 1 Gbps connection = 125 MBps. Internet providers advertise in Mbps (the bigger number) while file managers show MBps (the practical transfer rate).
How many bytes are in a 4.7 GB DVD?
Exactly 4,700,000,000 bytes (decimal). In binary, that is 4.38 GiB. In bits, it is 37.6 Gb. A 100 Mbps connection takes about 376 seconds (6.3 minutes) to download. At 1 Gbps, it takes 37.6 seconds. The quick-reference below the results shows this conversion along with other common file sizes.
Is a petabyte a lot of storage?
A petabyte (PB) = 1,000,000,000,000,000 bytes = 1,000 TB. That is about 13.3 years of HD video, or 250 million pages of text, or 500 billion pages of plain text. A typical consumer might use 1-2 TB per year. Data centres handle petabytes routinely. Google processes about 40,000 PB of searches per year.
Why do SSDs use decimal while RAM uses binary?
SSDs and hard drives are marketed using decimal (SI) because the numbers look larger. RAM is addressed in powers of 2 because memory controllers work with binary addressing. A 16 GB RAM stick actually has 16 x 1,073,741,824 = 17,179,869,184 bytes. But it is sold as '16 GB' because that is the standard marketing convention.