Data Size Converter
A data size converter turns one storage unit into another. It opens on the binary standard with 1 GiB in the From box and MiB in the To box, and answers 1,024. Press the decimal (1000) button and the same 1 GB becomes 1,000 MB. Both are correct: the two standards use different steps, 1024 and 1000.
Result
All Conversions
Storage Examples
Binary vs Decimal
| Binary | Value | Decimal | Value |
|---|---|---|---|
| 1 KiB | 1,024 B | 1 KB | 1,000 B |
| 1 MiB | 1,048,576 B | 1 MB | 1,000,000 B |
| 1 GiB | 1,073,741,824 B | 1 GB | 1,000,000,000 B |
| 1 TiB | 1,099,511,627,776 B | 1 TB | 1,000,000,000,000 B |
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About Data Size Converter
This converter works in bits internally, which is why it can move between bits, bytes and every prefix above them without rounding twice. Choose the standard first: the binary (1024) button gives you b, B, KiB, MiB, GiB, TiB and PiB, and the decimal (1000) button gives you b, B, KB, MB, GB, TB and PB. Then set From unit, To unit and a Value; the result appears immediately and a Copy result button puts it on your clipboard.
The two ladders are the reason storage numbers never seem to agree. IEC 60027-2, the standard NIST cites for the binary prefixes, defines a kibibyte as 1,024 bytes, a mebibyte as 1,048,576 bytes and a gibibyte as 1,073,741,824 bytes, while the SI prefixes kilo, mega and giga keep their decimal meaning of 1,000, 1,000,000 and 1,000,000,000. Drive manufacturers sell in decimal units; most operating systems report in binary ones. That single disagreement is why a 1 TB disk shows up as roughly 931 GiB.
Three panels help you read the answer. All conversions lists your value in every unit of the current standard at once. Storage examples places it against a 1.44 MB floppy, a 700 MB CD, a 4.7 GB DVD, a 25 GB Blu-ray, a 64 GB USB stick and a 1 TB SSD. The Binary vs decimal table on the Reference tab lines the two ladders up tier by tier. A precision control sets how many decimal places the result carries, and very small results switch to exponential notation instead of collapsing to zero.
What it does not do: it converts sizes, not transfer speeds, and it does not know about filesystem overhead, so the space a drive actually offers after formatting is always a little less than any figure here.
Use Cases
How to use
Pick the standard first: press binary (1024) for KiB, MiB and GiB, or decimal (1000) for KB, MB and GB.
Choose the From unit and the To unit in the two dropdowns. Bits are the lower-case b, bytes the upper-case B.
Type the number into the Value box. The result updates as you type, with no button to press.
Adjust Precision if the answer needs more or fewer decimal places, then press Copy result to put it on your clipboard.
Read the All conversions panel to see the same value in every unit, and Storage examples to place it against a CD, a DVD or a 1 TB drive.
Open the Reference tab for the Binary vs decimal table, which lines the two ladders up tier by tier.
Pro Tips
- The standard buttons keep your place in the ladder. Switching from binary to decimal with GiB selected leaves you on GB, not back at bytes, so you can compare the same tier directly.
- Precision defaults to 4 decimal places. Raise it before converting small values, because a result under 0.0001 is shown in exponential notation rather than rounded away.
- The lower-case b is bits and the upper-case B is bytes, and the converter treats them as a factor of 8 apart. Picking the wrong one is the most common way to be off by eight.
- The All conversions panel saves repeated work: it shows your value in every unit of the current standard at once, so you rarely need to change the To unit at all.
- Use the swap control rather than retyping when you want the inverse. It exchanges the From and To units and recalculates without touching the value you entered.
Troubleshooting
The result is 1,024 but I expected 1,000.
You are on the binary standard, where each step is 1024. Press the decimal (1000) button and the same conversion gives 1,000. Neither is wrong: operating systems usually report binary units and drive makers sell in decimal ones, which is the whole reason this page has two buttons.
The answer came back as something like 9.5e-7.
Results below 0.0001 are shown in exponential notation so they are not rounded to zero. Raise the Precision control, or convert into a smaller unit — bits or bytes instead of gigabytes — so the number lands in a readable range.
My converted figure is eight times too big or too small.
You have mixed bits and bytes. In both dropdowns the lower-case b is a bit and the upper-case B is a byte, and there are 8 bits in a byte. Check which one is selected in From unit and To unit and convert again.
Frequently Asked Questions
Pick the standard, then the two units. On the decimal (1000) button, 1 MB is 1,000 KB, so a 2,500 KB file is 2.5 MB. On the binary (1024) button the same tier reads 1 MiB = 1,024 KiB. Type the number into Value and the result appears without pressing anything.
A megabyte is 1,000,000 bytes; a mebibyte is 1,048,576 bytes, which is 2 to the power of 20. NIST cites IEC 60027-2 for the binary prefixes kibi, mebi and gibi. The gap is about 4.9% at this tier and grows with every step up the ladder.
Because the two sides use different ladders. The manufacturer sells 1 TB meaning 1,000,000,000,000 bytes, and the operating system divides that by 1,073,741,824 to report gibibytes, which gives roughly 931 — usually labelled GB even though it is really GiB. Nothing is missing; the unit changed.
1,000 in the decimal standard and 1,024 in the binary one. The converter opens on binary with 1 GiB in the From box and MiB in the To box and answers 1,024; press decimal (1000) and 1 GB gives 1,000 MB. Both are shown because both are in daily use.
One byte is eight bits, and the two dropdowns distinguish them by case: lower-case b is a bit, upper-case B is a byte. Internet speeds are usually quoted in bits per second and file sizes in bytes, which is why a 100 Mb/s line downloads at about 12.5 MB/s.
Seven per standard. Binary gives b, B, KiB, MiB, GiB, TiB and PiB; decimal gives b, B, KB, MB, GB, TB and PB. Switching standards keeps you on the same tier, so GiB becomes GB rather than resetting to bytes.
It depends what the data is, so do the arithmetic rather than trusting a rule of thumb. If you count a page of unformatted text as about 2 KB, then 2 MB is roughly 1,000 pages. For a physical comparison, the Storage examples panel places 2 MB against a 1.44 MB floppy disk and a 700 MB CD, so it is a little more than one floppy and a small fraction of a CD.
Both usages exist, which is exactly the problem the binary prefixes were created to fix. Strictly, a kilobyte is 1,000 bytes and 1,024 bytes is a kibibyte. In practice many programs still print KB when they mean KiB, so check which ladder a number came from before comparing it.
Yes. The All conversions panel under the result lists the value you typed in every unit of the current standard, with the unit you selected as To unit highlighted. It saves changing the To unit repeatedly when you are trying to find the most readable size.
No, it converts quantities of data, not rates. To turn a size into a time, divide by the speed after making the units agree: a 1.2 GB download over a 100 Mb/s line is 1.2 x 8,000 megabits divided by 100, about 96 seconds before any overhead.