Question 1

Why does my 1 Terabyte hard drive only show 931 Gigabytes of usable space on my computer?

Accepted Answer

This discrepancy is caused by the difference between decimal (base-10) and binary (base-2) mathematics. Hard drive manufacturers sell space in base-10, where 1 Terabyte is exactly 1,000,000,000,000 bytes. However, Windows computers read data in base-2, where a Gigabyte is $1,024 	imes 1,024 	imes 1,024$ bytes (1,073,741,824 bytes). When the computer divides the manufacturer's one trillion bytes by 1,073,741,824, the result is exactly 931.32 Gigabytes. You have not lost any physical space; the computer is simply using a larger mathematical ruler to measure the exact same physical area.

Question 2

How do I convert Mbps (Megabits per second) to MB/s (Megabytes per second)?

Accepted Answer

To convert Megabits to Megabytes, you must divide the number by 8, because there are exactly 8 bits in every single byte. For example, if your internet connection is rated at 400 Mbps, you divide 400 by 8 to get 50 MB/s. This means under perfect conditions, you can download 50 Megabytes of data every second. Understanding this conversion is crucial because network speeds and video bitrates are always measured in bits, while file sizes on your hard drive are always measured in bytes.

Question 3

How many photos can I fit on a 256 GB smartphone?

Accepted Answer

To calculate this, you must first determine usable space and average file size. A 256 GB phone typically loses about 20 GB to the operating system and base-2 conversion, leaving roughly 236 GB (241,664 MB) of usable space. If you shoot standard 12-megapixel HEIC or JPEG photos, the average file size is about 3.5 MB. Dividing 241,664 MB by 3.5 MB yields approximately 69,046 photos. If you shoot in high-resolution RAW format (roughly 25 MB per photo), that number drops significantly to about 9,666 photos.

Question 4

Does formatting an SD card or hard drive reduce its total capacity?

Accepted Answer

Yes, formatting a drive inherently reduces the amount of space available for your personal files. When a drive is formatted, the system creates a "File Allocation Table" (like a master index in a library) that tracks exactly where every piece of data is physically stored on the disk. This index, along with file system metadata, consumes a small portion of the drive's total raw capacity. Depending on the file system used (NTFS, exFAT, APFS), you can expect to lose anywhere from a few dozen Megabytes to several Gigabytes of space to formatting overhead.

Question 5

How much storage space does a 2-hour 4K movie require?

Accepted Answer

The size of a video file depends entirely on its bitrate, not just its resolution. A heavily compressed 2-hour 4K movie streamed on Netflix operates at roughly 15 Mbps. Converting to bytes ($15 \div 8$), that is 1.875 MB per second, or 112.5 MB per minute. Multiplied by 120 minutes, the total size is roughly 13,500 MB, or 13.5 GB. However, an uncompressed 4K Blu-ray disc of the exact same 2-hour movie operates at a much higher bitrate of about 80 Mbps, resulting in a file size of roughly 72 GB.

Question 6

What is the difference between lossy and lossless compression when calculating storage?

Accepted Answer

Lossy compression permanently deletes non-essential data from a file to achieve a drastically smaller storage footprint. For example, converting a WAV audio file to an MP3 uses lossy compression, discarding frequencies the human ear cannot easily hear, reducing a 50 MB file to just 5 MB. Lossless compression, like a ZIP file or a FLAC audio file, uses mathematical algorithms to pack the data more tightly without deleting anything, allowing the original file to be perfectly reconstructed. Lossless files are larger than lossy files, typically only reducing the original file size by 40% to 50%, rather than the 90% reduction seen with lossy formats.

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