Data Storage Converter

Data storage converter: bits, bytes, and the KB vs KiB problem

This converter handles both conventions that storage uses — decimal (powers of 1,000) and binary (powers of 1,024) — across bits, bytes, kilo, mega, giga, tera, and petabytes. The toggle above switches the whole table between them. Below is exactly how the two systems differ and when each one is correct.

The base unit: a byte is 8 bits

Everything here is built on the byte, which is 8 bits. A bit is a single 1 or 0. Because marketing materials and engineers mix bits and bytes freely, the single most common error in storage math is forgetting the factor of 8. Speeds are bits; sizes are bytes.

Decimal prefixes (SI) — what storage is sold in

• 1 KB = 1,000 bytes
• 1 MB = 1,000 KB = 1,000,000 bytes
• 1 GB = 1,000 MB = 1,000,000,000 bytes
• 1 TB = 1,000 GB
• 1 PB = 1,000 TB

Binary prefixes (IEC) — what RAM and Windows use

• 1 KiB = 1,024 bytes
• 1 MiB = 1,024 KiB = 1,048,576 bytes
• 1 GiB = 1,024 MiB = 1,073,741,824 bytes
• 1 TiB = 1,024 GiB
• 1 PiB = 1,024 TiB

The mismatch grows at every level. A "1 GB" file counted in GiB is only 0.931 GiB, which is why a 256 GB phone shows roughly 238 GiB of usable space before the operating system is even installed.

Practical conversions you will actually do

• 4K video: about 0.375 GB (375 MB) per minute at 50 Mbps — useful for sizing storage cards.
• One hour of 320 kbps audio: about 144 MB (3,600 s × 320,000 ÷ 8 ÷ 1,000,000).
• A RAW photo: typically 25–50 MB; a JPEG of the same image, 5–12 MB.
• A database row of plain text: usually a few hundred bytes to a few KB.

Estimating bandwidth and transfer time

To size a transfer, convert the file to bits and divide by the link speed in bits per second. Real-world throughput is usually 60–80% of the rated speed once overhead and congestion are accounted for, so add a margin to any estimate you make from the raw maximum.

Related converters

• Time Converter — turn a transfer time in seconds into minutes or hours.
• Base64 Encoder — note Base64 inflates data by about 33% when encoding binary as text.
• Image Compressor — shrink files before you worry about storage limits.