Data Storage Unit Converter

Introduction to converting bits, bytes, and binary storage units

Enter a number, pick the unit it is 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 is the point: the reason a "1 TB" drive shows up as roughly 931 GiB in your file manager is not a defect or a scam, it is 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.

The converter is exact where it can be. Every unit carries its defined byte factor as a literal number, and each result is one division away from a single shared byte count, so no rounding is compounded from step to step. The row you entered and the row you asked for are both highlighted, and the raw byte total is printed on its own line so you always have an unrounded figure to work from.

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 two ladders touch in exactly one place — the byte — which is why a conversion such as GB to GiB has no shortcut and has to travel down one ladder and up the other.

How to use the data storage converter

1. Type the amount of data into Value — any number from zero upward, including decimals like 2.5.
2. Pick the Unit of the value it is currently expressed in, from bits up to tebibytes.
3. Pick a Unit to highlight if you want a one-line answer, for example GiB when you are checking a drive label.
4. Press Convert, or just keep typing — the result updates live. The table lists the same quantity in every supported unit, so you can read down to whichever one you need. Reset clears the form and returns both menus to their defaults.

Values below zero are rejected rather than silently converted, because a negative capacity has no physical meaning, and a value so large that it overflows double-precision arithmetic reports a warning instead of printing an infinity.

The byte-factor formula behind every conversion

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 to bits multiplies by eight:

and going the other way, a bit count 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. Because the binary factor at step is and the decimal factor is , the drift between a decimal unit and its binary twin grows geometrically:

That single expression produces the whole drift ladder: +2.4% at step 1 (KB versus KiB), +4.9% at step 2, +7.4% at step 3, and +9.95% at step 4 (TB versus TiB).

Worked example: converting 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 2.328306 GiB, 2,500,000 KB, or 20,000,000,000 bits — every row in the result is just that byte count divided by a different factor.

Reading the conversion table

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 did not expect, compare the decimal and binary rows first — most "missing" storage vanishes once you match the units.

Very small and very large results switch to scientific notation rather than being flattened to a row of zeros. One byte expressed in tebibytes is 9.094947e-13 TiB, which is genuinely informative; rounding it to four decimal places would print 0.0000 and throw the information away.

Comparison table of decimal and binary 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 a 1 TB drive shows up as 931 GiB

Many users notice that a "1 TB" drive appears as something like "931 GB" 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) while still printing the label "GB". Dividing 1,000,000,000,000 by 1,073,741,824 gives 931.32 — the number your file manager shows.
• 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 is a real loss, usually a few percent, and it stacks on top of the unit difference.

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 and how much is genuinely missing space.

Limitations and assumptions of this data storage converter

This is a capacity converter and nothing more, so keep a few 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 will not 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 and switch to scientific notation at the extremes, so when you need exact integers, work from the byte line rather than a rounded GiB value.

The converter assumes the standard 8-bit byte and the exact SI and IEC byte factors listed above. It does not model niche definitions such as the "1.44 MB" floppy disk, whose megabyte was 1,024,000 bytes — neither a true MB nor a true MiB. Arithmetic uses IEEE 754 double-precision numbers, which hold about 15–17 significant decimal digits, so byte counts beyond roughly 9 quadrillion (2⁵³) are approximations rather than exact integers, and inputs beyond about 1.8 × 10³⁰⁸ bytes are refused outright rather than reported as infinity.

Data storage conversion questions answered

Sources: Decimal (SI) prefixes follow the BIPM table of SI prefixes; binary (IEC) prefixes and the exact 1,024-based factors follow NIST's reference on prefixes for binary multiples and IEC 80000-13 (IEC prefixes for binary multiples). Byte factors used here are exact: KB/MB/GB/TB use powers of 1,000 and KiB/MiB/GiB/TiB use powers of 1,024.