Data Size Converter (KB, MB, GB, TB)
＋More features: download time and what fits in this space
Estimated download time
Enter a file size and your line speed (Mbps) to get both the theoretical time and a realistic estimate at an effective speed (70% of theoretical).
What fits in this much space
Uses the size entered in the form above to estimate how many photos, songs and hours of video it holds.
Type a number and see the same size expressed in KB, MB, GB and TB all at once. Computers count in steps of 1024 while product packaging counts in steps of 1000, so you can switch between the two and compare. Useful when the 500 GB drive you bought shows up as 465 GB, or when you are checking how much data your phone plan and storage actually give you.
How to use
- Enter the number and its unit.
- Choose the counting method (if in doubt, use 1024).
- Every unit is listed as soon as you type — no button needed.
How it is calculated
- 1024 counting: 1 KB = 1024 B, 1 MB = 1024 KB, and so on. This is what Windows and phone operating systems use to show file sizes (strictly speaking these units are called KiB and MiB).
- 1000 counting: 1 KB = 1000 B, 1 GB = one billion B, and so on. This follows the SI prefixes and is used for the capacity printed on HDDs, SSDs and USB drives.
- Worked example: a “500 GB” product (1000 counting) is 500,000,000,000 B. Shown by an OS in 1024 counting, that is about 465.7 GB — the difference between the two methods is the main reason capacity looks like it “shrank”.
Sources and assumptions
- Arithmetic based on the definitions of the SI prefixes (×1000) and the binary prefixes (×1024).
Assumptions and notes
- Real storage also uses space for system areas, so the usable capacity can be smaller still, beyond the difference between the two counting methods.
- The “1 GB” of a mobile data allowance is normally counted with 1000.
Frequently asked questions
The 500 GB SSD I bought shows as 465 GB on my computer. Is it faulty?
No. The product label uses 1000 counting (500,000,000,000 bytes) while your computer displays 1024 counting, so the same capacity reads as about 465.7 GB. Switch between the two methods in this tool to check.
How many MB is 1 GB?
1,024 MB with 1024 counting, and 1,000 MB with 1000 counting. In practice both are used, depending on the context.
Which counting does my phone data allowance use?
Mobile carriers normally count data with 1000 (1 GB = 1,000 MB). As a rough guide, one hour of video uses about 0.5 to 2 GB depending on quality.