Convert terabytes to megabytes

One terabyte is 1000000 megabytes. To convert any amount, multiply by 1000000. Going the other way, one megabyte is 0.000001 terabytes.

Multiply the terabyte figure by 1000000. So MB = TB × 1000000. For a quick mental estimate, multiplying by about 1000000 gets you within a percent or so, which is close enough for most everyday purposes.

One terabyte is a large photo and video library. A terabyte is a trillion bytes. Consumer drives are sold in decimal terabytes, which is why a '2 TB' drive shows as roughly 1.82 TiB once formatted.

One megabyte is a high-quality photo. A megabyte is one million bytes. Mobile data allowances, file sizes and download figures almost always use this decimal definition.

Because two different definitions are in play. Storage manufacturers use decimal units — 1 TB means exactly one trillion bytes. Windows and many other systems display binary units but label them with decimal names, so they show that same drive as 931 "GB" when they mean 931 gibibytes. Nothing is missing and nothing is faulty; the drive holds exactly what it says, measured differently. The IEC standardised kibi, mebi and gibi in 1998 specifically to end this, but adoption has been patchy.

Yes — both decimal and binary prefixes are exactly defined powers, so every figure here is exact rather than approximate. The results are shown to seven significant figures; the underlying arithmetic uses full double precision.