Data Storage Converter
Convert between bytes, KB, MB, GB, TB and PB in both binary and decimal — and finally understand why a 1 TB drive shows as 931 GB.
Why a “1 TB” drive shows less than 1 TB
If you have ever bought a 1 TB drive and watched your computer report only about 931 GB, you have met the most confusing thing in digital storage: there are two ways to count. Drive makers and internet providers use the decimal system where 1 TB = 1,000,000,000,000 bytes. Windows, RAM and many programs use the binary system where quantities step up in multiples of 1024. The bytes are identical — only the labels differ — so the same drive looks smaller once your OS divides by 1024 at each step.
This converter handles both. Toggle between binary and decimal and you can see exactly why the figures disagree, and convert cleanly between bits, bytes, KB, MB, GB, TB and PB.
Quick reference: storage units
| Unit | Binary (1024) | Decimal (1000) | Roughly holds |
|---|---|---|---|
| 1 KB | 1,024 bytes | 1,000 bytes | A short email |
| 1 MB | 1,048,576 bytes | 1,000,000 bytes | A high-quality photo |
| 1 GB | 1,073,741,824 bytes | 1,000,000,000 bytes | ~250 songs or 30 min HD video |
| 1 TB | 1,099,511,627,776 bytes | 1,000,000,000,000 bytes | ~250,000 photos |
Bits vs bytes catch. Internet speeds are quoted in megabits (Mb/s), but file sizes are in megabytes (MB). One byte is eight bits, so a 100 Mb/s connection downloads about 12.5 MB per second — not 100. Our download time calculator does that maths for you.
Frequently asked questions
Why does my hard drive show less space than advertised?
Manufacturers count storage in decimal (1 GB = 1,000,000,000 bytes) while Windows counts in binary (1 GB = 1,073,741,824 bytes). The drive holds exactly what it says in bytes; your operating system just divides by 1024 at each step, so the GB figure looks smaller. No space is missing.
What is the difference between a bit and a byte?
A byte is eight bits. Bits (lowercase b) are used for data-transfer speeds like 100 Mb/s; bytes (uppercase B) are used for file sizes like 500 MB. To convert a connection speed to download speed, divide the megabits by eight.
Should I use binary or decimal?
Use decimal (1000) when talking about drive capacity, internet plans and most marketing figures. Use binary (1024) when matching what Windows, RAM or many file managers report. This tool lets you switch and compare instantly.
How many photos or songs fit in a GB?
Roughly 250 standard songs, around 600 high-resolution photos, or about 30 minutes of 1080p video per gigabyte. Exact counts vary with quality and format, so treat these as planning estimates.
What comes after a terabyte?
A petabyte (PB) is 1024 terabytes in binary, or 1000 TB in decimal. Beyond that are the exabyte, zettabyte and yottabyte — sizes used for data centres rather than personal devices.
This tool runs entirely in your browser — nothing you type is sent to our servers. Tudug is reader-supported and may earn from ads.
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