Free online data storage converter. Convert bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes — both binary (IEC) and decimal (SI) standards supported. Tap a quick conversion or see what your storage actually holds.
Bits • Bytes • KB • MB • GB • TB • PB
Know exactly how many photos, songs, or movies fit on any drive — with real-world file size context.
Convert Mbps (megabits/sec) to MB/s for download speed calculations — bits ≠ bytes!
Understand why your "1 TB" drive shows as 931 GB in Windows — binary vs decimal mismatch explained.
Data storage conversions confuse people for two reasons: the binary vs decimal distinction, and the fact that bits ≠ bytes. Internet speeds are measured in bits (Mbps = megabits per second) while file sizes are measured in bytes (MB = megabytes). To convert download speed to file transfer rate: divide Mbps by 8 to get MB/s. A 100 Mbps connection downloads files at 12.5 MB/s.
Binary (IEC standard, used by OS): 1 KB = 1,024 bytes. 1 MB = 1,048,576 bytes. 1 GB = 1,073,741,824 bytes. 1 TB = 1,099,511,627,776 bytes. Decimal (SI standard, used by storage manufacturers and telecom): 1 KB = 1,000 bytes. 1 MB = 1,000,000 bytes. 1 GB = 1,000,000,000 bytes. 1 TB = 1,000,000,000,000 bytes. A "1 TB" hard drive (decimal) = 0.909 TB binary = 931 GB as Windows reports it.
Photo (JPEG): 3–6 MB. RAW photo: 20–50 MB. Song (MP3): 4–8 MB. Song (FLAC): 25–40 MB. HD movie: 4–8 GB. 4K movie: 50–100 GB. App install: 50–5,000 MB.
100 Mbps → 12.5 MB/s (÷8). 1 Gbps → 125 MB/s. 25 Mbps → 3.1 MB/s. A 2 GB movie at 100 Mbps takes: 2,000 MB ÷ 12.5 MB/s = 160 seconds = 2.7 minutes.
Typical phone: 128–512 GB. Laptop SSD: 256 GB–2 TB. External drive: 1–20 TB. Enterprise NAS: 100 TB+. Cloud free tiers: 5–15 GB. 1 TB holds ≈ 250,000 photos or 500 HD movies.
RAM is measured in binary: 8 GB RAM = 8,589,934,592 bytes. Storage is decimal: 8 GB SSD = 8,000,000,000 bytes. RAM is 7.4% larger than advertised storage at the same "GB" label. Your OS uses binary for both.
Digital storage is the only area where two incompatible definitions of the same prefix are both in daily use. Drive manufacturers use decimal SI prefixes, where a gigabyte is 10⁹ bytes, while operating systems have traditionally reported binary multiples, where the same quantity is 2³⁰ bytes. The gap compounds with each prefix: 2.4% at kilo, 4.9% at mega, 7.4% at giga and 10% at tera. This is the entire explanation for the "missing" capacity on a new drive — nothing is lost, the two parties are counting differently. IEC introduced kibi, mebi and gibi in 1998 to disambiguate, and adoption remains partial.
bytes = value × factorDecimal: 1 kB = 10³ · 1 MB = 10⁶ · 1 GB = 10⁹ · 1 TB = 10¹²Binary: 1 KiB = 2¹⁰ · 1 MiB = 2²⁰ · 1 GiB = 2³⁰ · 1 TiB = 2⁴⁰1 byte = 8 bitswhere:
Assumptions: macOS and most storage vendors report decimal; Windows reports binary while labelling it "GB". Network throughput in Mbps is megabits, so divide by 8 to compare with file sizes in megabytes.
Trace the arithmetic behind the most common storage complaint.
Result500 GB = 465.66 GiB — the same bytes, two conventions
Formatting overhead is a separate and much smaller deduction, typically well under 1%. If a drive reports meaningfully less than 465 GiB after formatting, that is a genuine issue rather than a units artefact.