Digital Data Conversion Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/5/2026
To convert a data quantity, it's brought back to a common unit (the byte) then converted into the new unit. For example, 1 GB represents 1,000 MB (decimal convention).
Explanation
This calculator uses the decimal convention of the International System (SI), where each unit is worth 1,000 times the previous one: 1 kilobyte (KB) = 1,000 bytes, 1 megabyte (MB) = 1,000 KB, and so on. This is the convention used by storage manufacturers (hard drives, USB drives, SD cards) on their packaging. There is another, binary convention, where each unit is worth 1,024 times the previous one (used internally by some operating systems, which sometimes call 'KB' what is actually a kibibyte, or 'KiB') — see the FAQ for the details of this difference, which explains why a '1 TB' hard drive often shows a slightly lower usable capacity once plugged into a computer.
Example: converting 1 GB to MB
Inputs
Value: 1. Starting unit: GB. Target unit: MB.
Calculation
1 GB × 1,000,000,000 bytes per GB = 1,000,000,000 bytes. Dividing by 1,000,000 (the MB factor) gives 1,000 MB.
Result
1 GB represents 1,000 MB under the decimal convention.
Frequently asked questions
Why does my '1 TB' hard drive show less space once plugged in?
Because manufacturers advertise capacity using the decimal convention (1 TB = 1,000,000,000,000 bytes), while operating systems often display space using the binary convention (where the unit they call 'TB' is actually worth 1,099,511,627,776 bytes). The drive does contain the advertised amount of data, but it's displayed under a slightly different unit — hence the visible gap, which can reach about 7% at this scale.
Does this calculator use the decimal or binary convention?
This calculator uses the decimal convention (1 KB = 1,000 bytes), the one used by storage manufacturers and the International System of Units. If you're trying to exactly match an operating system's display (often in binary convention, 1,024), the result may differ slightly from what your computer shows.
How many bytes are there in a megabyte?
Under the decimal convention (used here), 1 megabyte (MB) equals exactly 1,000,000 bytes, or 1,000 kilobytes. Under the binary convention, a mebibyte (MiB) equals 1,048,576 bytes — a difference of about 5% at this scale.