Free Data Storage Converter Online

A data storage converter answers a question that trips up more people than it should: does a 4.7 GB file actually fit on a device that reports 4 GB free? The honest answer depends on which definition of "GB" both numbers are using, because storage sizes get counted two different ways depending on where the number came from — and this tool is explicit about which one it uses. Type a value in bits, bytes, kilobytes, megabytes, gigabytes, or terabytes, pick the unit you're starting from, and every other unit's equivalent appears immediately, calculated on the binary (1,024-based) convention throughout.

How the Data Storage Converter Works

The browser tool takes a single number in gigabytes and instantly fills in the equivalent in gigabits, megabytes, kilobytes, bytes, terabytes, and petabytes below it — recalculating automatically as you type, with no separate "convert" step needed unless you switch off the automatic mode with the toggle at the top. Every one of those conversions is computed on the binary basis: multiplying up by exactly 1,024 at each step, not 1,000.

• Instant, all-units output. Rather than choosing a single target unit from a dropdown, the results panel lists every common unit's equivalent at once, so you don't need to already know which unit you'll actually need before running the conversion.
• Copy and download. A copy button next to the results pastes the full set of conversions to your clipboard in one click, and a save button downloads them as a plain text file for pasting into a report or ticket.
• File upload as an alternative input. Rather than typing a number by hand, a file can be dropped onto the input pane and its size read automatically, which is handy for checking a specific file's size across units without looking up the byte count separately first.

The metered API endpoint, documented at /docs, exposes a more direct version of the same binary math. Pass the figure to convert, the unit it starts in, and the unit you need — bit, byte, KB, MB, GB, or TB — attach an Authorization header carrying your key (Bearer token or X-API-Key, either works), and what comes back is the converted figure along with every other unit's equivalent. Each call costs one credit, which fits neatly into a backend that needs to normalize file sizes reported inconsistently across an upload pipeline, a billing system, or a storage-quota dashboard.

Why People Convert Data Storage Units

Situations where getting the right number, in the right convention, actually matters:

• Checking whether a download will fit on a device. A phone or USB drive reporting "12 GB free" and a video file listed as "11.5 GB" look like they should fit — but if the two figures were computed under different conventions, the margin is thinner than it looks, or occasionally not there at all.
• Understanding why a new hard drive shows less space than advertised. A drive sold as "1 TB" and then reporting roughly 931 GB of usable space in an operating system's file browser hasn't lost storage to some hidden overhead — it's the exact same number of bytes, described under two different counting conventions.
• Sizing a cloud storage or backup plan. Comparing a photo library's reported size against a subscription tier's stated limit requires knowing both figures are using the same convention, especially when the numbers are close to a plan's boundary.
• Estimating RAM or video file requirements. Video editors and developers sizing a project's memory or storage needs often work from a raw byte count and need it expressed in GB or MB to communicate with a client or teammate in familiar terms.
• Reading network and bandwidth figures correctly. Internet speeds are typically advertised in bits per second while file sizes are measured in bytes, and converting between the two (a factor of 8) is a common point of confusion when estimating how long a download will actually take.

Technical Deep Dive: Binary vs. Decimal, and Why Both Exist

This converter uses the binary convention: 1 KB = 1,024 bytes, 1 MB = 1,024 KB = 1,048,576 bytes, 1 GB = 1,024 MB = 1,073,741,824 bytes, and 1 TB = 1,024 GB = 1,099,511,627,776 bytes. That choice isn't arbitrary — computer memory and file systems are built around powers of two, so a storage size that's a round number in binary (a full megabyte of RAM, for instance) is genuinely a round number to the hardware, not just to a human reading it. This is also how most operating systems report file and drive sizes on screen.

Hard drive and flash storage manufacturers, by contrast, have long used the plain decimal convention instead: 1 KB = 1,000 bytes, 1 MB = 1,000,000 bytes, and so on, following the ordinary metric meaning of kilo-, mega-, and giga-. Neither convention is "wrong" — they're both internally consistent, just built for different purposes — but mixing them without realizing it is exactly what produces the familiar surprise of a "1 TB" drive showing up as roughly 931 GB once an operating system reports it using binary math instead. The gap between the two conventions isn't fixed either: it's about 2.4% at the kilobyte level (1,024 vs. 1,000), but it compounds at every step up the scale, reaching roughly 7% by the gigabyte level and just under 10% by the terabyte level — which is exactly why the discrepancy becomes noticeable on larger drives and easy to miss on smaller files.

To remove the ambiguity, an international standards body formally defined a separate set of binary-specific prefixes in the late 1990s — kibibyte (KiB), mebibyte (MiB), gibibyte (GiB) — specifically so "kilobyte" could keep its plain decimal meaning while a distinct term unambiguously meant the 1,024-based figure. In practice, everyday usage still calls the binary figure "GB" far more often than "GiB," which is exactly why stating the convention explicitly, the way this tool does, matters more than the label alone.

An honest side-by-side of the two conventions at a few common sizes:

Size	Binary (1,024-based)	Decimal (1,000-based)	Gap
1 "KB"	1,024 bytes	1,000 bytes	2.4%
1 "MB"	1,048,576 bytes	1,000,000 bytes	4.9%
1 "GB"	1,073,741,824 bytes	1,000,000,000 bytes	7.4%
1 "TB"	1,099,511,627,776 bytes	1,000,000,000,000 bytes	10.0%

Comparing Ways to Check Storage Figures

A few approaches to working out a storage size, and where each one falls short:

• Trusting the label on the box. Accurate for the raw byte count a manufacturer intends, but stated in the decimal convention, which won't match what an operating system reports once the drive is formatted and mounted.
• Reading the operating system's file properties dialog. Reliable and immediate for a file already on your device, but only tells you about that one file — not useful for planning ahead of a download or comparing against a plan's stated limit.
• Manual multiplication by 1,024 or 1,000. Works fine for a single conversion done carefully, but easy to mix up which convention applies partway through a longer calculation involving several unit jumps.
• A dedicated data storage converter. Handles every unit jump consistently under one explicitly stated convention, removing the guesswork about which multiplier applies at each step.

How Your Numbers Are Handled

Every figure you type, and any file you drop in just to read its size, is processed locally in your browser — nothing is uploaded to a server or stored anywhere afterward. There's no account requirement, refreshing the page clears the fields instantly, and the tool places no limit on how many conversions you run.

Common Questions About Data Storage Units

Why does my 1 TB hard drive show up as roughly 931 GB in Windows or macOS?

Because the manufacturer's "1 TB" label uses the decimal convention (1 TB = 1,000,000,000,000 bytes), while Windows and macOS report drive capacity using the binary convention (1 TB = 1,099,511,627,776 bytes). It's the exact same physical storage — the same number of bytes — just described under two different, equally valid counting systems.

Is 1 GB equal to 1,000 MB or 1,024 MB?

Both answers are correct depending on convention — 1,000 MB under the decimal system storage vendors typically use, or 1,024 MB under the binary system this converter and most operating systems use. This tool sticks to binary throughout, so 1 GB here always equals 1,024 MB, never 1,000.

What do KiB, MiB, and GiB actually mean, and are they the same as KB, MB, and GB?

KiB, MiB, and GiB are the formally standardized binary-specific units (1,024-based), created to remove ambiguity from the everyday KB/MB/GB labels, which get used loosely for both conventions in practice. When this tool shows "GB," it means the binary figure — functionally identical to a GiB — even though it uses the more familiar everyday label.

Does this converter use binary or decimal math?

Binary, consistently, across every unit it supports: each step up from bit to byte to kilobyte to megabyte to gigabyte to terabyte multiplies by 1,024 (or, going from bit to byte, by 8), matching how most operating systems report file and drive sizes on screen.

Why does the browser tool show petabytes but the API's unit list stops at terabytes?

The browser tool's results panel adds a petabyte figure purely as a bonus reference point, since a value large enough to matter at the petabyte scale is rare outside data-center contexts. The API keeps its supported unit list to bit, byte, KB, MB, GB, and TB — the range that covers the overwhelming majority of real file, drive, and transfer sizes anyone is likely to convert programmatically.

How many bytes are in a bit, and why do internet speeds get advertised in bits rather than bytes?

One byte equals 8 bits, and the practice of advertising connection speed in bits per second rather than bytes per second is a long-standing networking convention. It means a "100 Mbps" connection downloads at roughly 12.5 megabytes per second, not 100 — a factor-of-8 mix-up that catches out anyone estimating download time from an advertised speed figure.

Why does a phone listed as "128GB" often show noticeably less space actually available?

Two separate effects combine here: the binary-versus-decimal gap accounts for part of the shortfall, and the operating system, pre-installed apps, and system reserved space account for the rest. The decimal-versus-binary gap alone typically explains only a portion of what feels like "missing" storage on a new device.

Related Tools

Everyday length and distance conversions between metric and imperial units are handled by the Length Converter, and weight or mass conversions follow the same kind of fixed-ratio math over at the Weight Converter. Estimating how long a download or file transfer will take once its size is known pairs naturally with the Time Unit Converter, network and audio frequency figures in Hz, kHz, or MHz are covered by the Frequency Converter, and temperature readings on a device or server rack are handled separately by the Temperature Converter.