File Size Converter | DailyTipsFinder

What this calculator does

File size units look straightforward and contain one genuine ambiguity that causes endless confusion. There are two competing conventions for how many bytes make a kilobyte, and both are in legitimate everyday use.

Operating systems count in powers of two, so a kilobyte is 1,024 bytes, a megabyte is 1,024 kilobytes, and so on. Storage manufacturers count in powers of ten, so a kilobyte is 1,000 bytes. Neither is wrong, but they produce different numbers, and the gap widens at each level. At terabyte scale it reaches about seven per cent.

This converter handles both. Enter any amount in any unit, choose the convention, and it converts across the full range from bits to terabytes, and shows you what the same size looks like under the other convention.

How the calculation works

Everything is converted to bytes first, then divided out into each target unit. The multiplier is either 1,024 or 1,000 depending on the convention you select, applied once per level.

Bits are handled separately because they are one eighth of a byte. Network speeds are quoted in bits per second while file sizes are quoted in bytes, which is why a connection speed and a download rate look so different even when they describe the same transfer.

The comparison against the other convention is included deliberately, because it answers the question that brings most people here: why does a drive advertised as one size show a smaller number once it is connected.

The formula

Binary convention: 1 KB = 1,024 B · 1 MB = 1,024 KB · 1 GB = 1,024 MB · 1 TB = 1,024 GB

Decimal convention: 1 KB = 1,000 B · 1 MB = 1,000 KB · 1 GB = 1,000 MB · 1 TB = 1,000 GB

Bits to bytes: 8 bits = 1 byte

A worked example

A drive is sold as 1 TB. Under the decimal convention the manufacturer used, that is 1,000,000,000,000 bytes.

Your computer divides by 1,024 three times to reach gigabytes: 1,000,000,000,000 divided by 1,073,741,824 gives 931.32 GB. That is the number shown in the file manager, and it is why a brand new drive appears to be missing nearly seventy gigabytes.

The same logic at smaller scale. A 16 GB memory card holds 16,000,000,000 bytes by the manufacturer count, which your phone reports as about 14.9 GB. Formatting overhead and system files then take a further slice, which is why usable space is lower again.

Things worth knowing

Both conventions are legitimate

Manufacturers are not being deceptive when they use powers of ten. It is an established convention, and the standards bodies define it. The confusion comes from operating systems using a different one without saying so.

Formatting takes a further slice

Beyond the unit conversion, a file system needs space for its own structures, and devices reserve capacity for system files. Usable space is always somewhat below the figure your file manager reports.

Networks speak in bits

Connection speeds are in bits per second, file sizes are in bytes. Divide by eight to move from one to the other. This single conversion explains most confusion about why downloads seem slower than the package.

Check units before buying storage

When comparing devices or cloud plans, confirm which convention each one uses. A plan quoted in decimal gigabytes offers about seven per cent less than the same number in binary gigabytes.

Common mistakes to avoid

Assuming there is only one definition of a gigabyte.
Confusing bits with bytes, which differ by a factor of eight.
Expecting a new drive to show exactly its advertised capacity.
Forgetting that formatting and system files reduce usable space further.
Comparing two storage products without checking which convention each uses.

Frequently asked questions

How many MB are in a GB?

1,024 under the binary convention used by operating systems, or 1,000 under the decimal convention used by storage manufacturers. Both answers are correct within their own convention, which is why the question causes so much confusion.

Why does my 1 TB drive show 931 GB?

The manufacturer counted 1,000,000,000,000 bytes as one terabyte. Your operating system divides by 1,024 three times rather than 1,000, which yields 931.32 GB. Nothing is missing.

What is the difference between Mb and MB?

A lowercase b means bits and an uppercase B means bytes. Mb is megabits, used for network speeds. MB is megabytes, used for file sizes. One MB equals eight Mb.

How large is a typical photo or video?

A phone photo is commonly 2 to 5 MB. A minute of 1080p video is roughly 100 to 200 MB depending on the encoding, and 4K video can be several times that. Sizes vary widely with camera settings and compression.

What is a gibibyte?

The formal name for the binary gigabyte, written GiB, equal to 1,073,741,824 bytes. It exists precisely to remove this ambiguity, though it has never caught on in everyday use.