SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/tech-1tb-shows-931gb

Your new 1 TB drive shows up in Windows as about 931 GB. Why?

Drive makers use decimal units, while Windows labels binary units as GB. No space is missing.

Start playing free

  1. The maker shorted you 69 GB
  2. Decimal vs binary ways of counting ✔
  3. Hidden viruses use the space

Why: Drive makers call 1,000,000,000 bytes a GB. Windows divides by 1,073,741,824 but still labels the result GB. The same 1 TB drive therefore appears as about 931 GB.

Huh, didn't know that: Seagate's conversion table shows a marketed 1 TB drive as about 931 GB in Windows.

The dad joke
Why did the computer show up late? It had a hard drive.
Like this card?
Play the game

References

Answer: Decimal vs binary ways of counting. Drive makers call 1,000,000,000 bytes a GB. Windows divides by 1,073,741,824 but still labels the result GB. The same 1 TB drive therefore appears as about 931 GB.

  1. Why does my hard drive report less capacity than indicated on the drive's label? (Seagate) www.seagate.com/support/kb/why-does-my-hard-drive-report-less-capacity-than-indicated-on-the-drives-label-172191en
    Hard drive manufacturers market drives in terms of decimal (base 10) capacity.
    Checked 2026-10-11.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

Tech & GadgetsCan a typical refrigerator magnet erase the hard drive on a laptop?Tech & GadgetsYou're storing a tablet long term. About how charged should its battery be?Tech & GadgetsDoes a bigger charger charge faster?

That's stuff everyone should know.