Data Storage Unit Converter

Making sense of bits, bytes, and everything above them

Enter a number, pick the unit it's in, and this converter shows the same quantity of data expressed in every other unit at once — bits, bytes, and the whole ladder up to terabytes, in both the decimal and binary flavors. Each unit gets its own row, so GB sits directly beside GiB and TB beside TiB. That's the point: the reason a "1 TB" drive shows up as roughly 931 GiB in your file manager isn't a defect or a scam, it's two measuring systems disagreeing about what a "giga" means, and reading straight down the list tells you how much of any capacity gap is pure terminology.

Bits, bytes, and the two prefix systems

Everything a computer stores is a string of bits — each one a single 0 or 1. Eight bits make a byte, historically the space needed to hold one character of plain text. From there the units grow in two parallel families that share names but not values:

• Decimal (SI): KB, MB, GB, TB — each step multiplies by 1,000. Drive makers, network gear, and cloud quotas almost always use these.
• Binary (IEC): KiB, MiB, GiB, TiB — each step multiplies by 1,024 (a power of two). Windows, Linux, and most low-level tools report sizes this way, even when they lazily print the label "GB".

Both families are correct; they just count in different bases. The gap between them widens at every step: a kilobyte and a kibibyte differ by only 2.4%, but a terabyte and a tebibyte differ by almost 10%. The converter carries the exact byte factor for each unit, so any pairing lands on the right number.

How the conversion works

Rather than juggle a separate rule for every pair of units, the calculator does one thing: it turns your input into a raw count of bytes, then divides that count by the byte-size of each target unit. Writing V_source for your value, F_source for the bytes in one source unit, and F_target for the bytes in one target unit, every result comes from a single ratio:

The bit is the only unit smaller than a byte, so it is worth stating on its own. Converting a byte count $S$ to bits multiplies by eight:

and going the other way, a bit count $b$ becomes bytes by dividing by eight:

The byte factors the converter plugs into F are exactly the standard definitions: 1,000 / 1,000,000 / 1,000,000,000 / 1,000,000,000,000 bytes for KB / MB / GB / TB, and 1,024 / 1,048,576 / 1,073,741,824 / 1,099,511,627,776 bytes for KiB / MiB / GiB / TiB.

Worked example: 2.5 GB to MiB

Say a download is listed as 2.5 GB (decimal) and you want it in mebibytes. First turn gigabytes into bytes:

then divide by the size of one MiB:

Notice the number went up: because a MiB is smaller than a GB by a factor of about 953, it takes more of them to hold the same data. The same 2,500,000,000 bytes is also 2.5 GB, about 2.33 GiB, or 20,000,000,000 bits — every row in the result is just that byte count divided by a different factor.

Reading your results

A few patterns make the output easier to trust. Converting down toward bits or bytes always produces big numbers — that is just how many individual pieces the data breaks into, not a sign of an error. Converting up toward GB or TB from a small file usually gives a value below 1, which reads as a fraction of the larger unit. And the decimal/binary twins (GB vs GiB, MB vs MiB) will always land close but never equal, with the binary value slightly smaller because a GiB holds more bytes than a GB. When a drive or phone reports a capacity you didn't expect, compare the decimal and binary rows first — most "missing" storage vanishes once you match the units.

Comparison table of common data storage units

The table lists every unit the converter supports and the exact byte count behind it, in whichever system defines it. Bits are shown as a fraction of a byte to keep one consistent base.

Why does my device show less storage than advertised?

Many users notice that a “1 TB” drive appears as something like “931 GiB” or similar in their operating system. This is usually not an error. It is a combination of two effects:

• Different units: Manufacturers typically label drives using decimal TB (1 TB = 1,000,000,000,000 bytes), whereas operating systems often display sizes in binary GiB (1 GiB = 1,073,741,824 bytes). The same number of bytes therefore corresponds to different numeric values depending on which unit is used.
• Reserved space and formatting: File systems, metadata, and recovery partitions also occupy part of the total capacity, leaving less usable space for your own data.

This converter helps you isolate the unit difference by letting you convert between TB and TiB, GB and GiB, and related pairs, so you can see how much of the discrepancy is just terminology.

What it doesn't cover

This is a capacity converter and nothing more, so keep two limits in mind. It has no notion of transfer speed — units like Mbps or MB/s measure how fast data moves, not how much of it there is, and the tool won't tell you how long a download takes. It also ignores real-world overhead: file systems, partition tables, and reserved recovery areas quietly claim part of a drive, which is why formatted capacity is always a little below the raw number here. Displayed figures are rounded for readability, so when you need exact integers, work from the byte row rather than a rounded GiB value.

Using the converter

1. Type the amount of data into Value — any positive number, including decimals like 2.5.
2. Pick the Unit it is currently expressed in, from bits up to tebibytes.
3. Press Convert. The result table lists the same quantity in every supported unit, so you can read down to whichever one you need — for instance GB right beside GiB to explain a capacity mismatch.