Why hard drives and USB drives have less storage space than advertised?

We all have purchased storage devices a number of times in your life, and we often get disappointed with less than the rated storage capacity, when we connect the same to our computers or other electronic devices. We all got disappointed by it, the first time we purchased a 16 GB flash drive or a 500 GB hard drive.

The more the storage, the more the space we miss, on our storage devices. On a 1 TB hard drive, we get close to around 930 GB, instead of 1024 GB, which means, we don’t get close to 100 GB of storage.

When this seems to be a big number, we often ask the shopkeeper or the salesperson about it, and they try to water up to our inquisitiveness saying, the missing space is inaccessible as it contains the drivers, system files and everything rubbish, the reality, however, is nowhere close to that.

In most cases, they themselves don’t know the reason behind it, and so I am here to tell you the actual reason, why you shouldn’t worry about the missing space. You are not at all getting deceived by the shopkeeper or so. Once you know the reason, you will no longer complain about the missing space.

Why the capacities of storage devices differ on our gadgets from marketed capacities?

So let’s demystify the missing space on the storage devices available in the market.

Let’s just consider, you have got a 16 or 32 GB flash drive. You will expect exactly the same amount of storage on your devices, applying the calculation, you have learned in your high school or college. That is correct, and below is the way, we calculate storage spaces on the devices.

1 byte = 8 bits

1024 bytes = 1 KiloByte

1024 KiloByte = 1 MegaByte

1024 MegaByte = 1 GigaByte

1024 GigaByte = 1 TeraByte

I am keeping away the bigger units of storage away for the sake of our calculation, as it goes on in the same and stereotyped way.

Let me consider, you have got 32 GB flash drive for yourself. The number of bytes, which you should get, is as below.

32 GB = 32 × 1024 × 1024 × 1024 = 34,359,738,368 bytes.

So we, our computer knows, a 32 GB storage device should have that number of bytes.

Let’s now look at, how the storage device manufacturers calculate storage space on devices.

1 byte = 8 bits

1000 bytes = 1 KiloByte

1000 KiloByte = 1 MegaByte

1000 MegaByte = 1 GigaByte

1000 GigaByte = 1 TeraByte

So they keep away the frustrating 24 for the ease of manufacturing the storage devices.

That being said, a 32GB storage device manufactured by a company should have the following number of bytes.

32 GB (as per the manufacturers) = 32 × 1000 × 1000 × 1000 = 32,000,000,000 bytes.

But, our lovely little computers and smartphones don’t understand such manufacturing optimizations and calculate the storage spaces, the way we do.


So, an actual 32 GB storage device, when connected to our electronic gadgets, will show a smaller number as our gadgets will find only 32,000,000,000 bytes instead of that big chunky number I calculated some time ago.

32,000,000,000 bytes, when converted to Giga Bytes comes out to be the following number if the appropriate calculation is applied.

32,000,000,000 ÷ (1024 × 1024 × 1024)

= 29.80 GB

This number is close to the available space, you will get, next time you purchase a 32 GB flash drive.

The same is applicable for storage devices with different capacities. It is applicable for almost all types of storage devices, you will come across, no matter whether they are hard drives, solid state drives or flash drives. It isn’t a mystery at all, so better don’t worry.

The next time you purchase a storage device for your requirements, keep this thing in mind and choose the most appropriate capacity to suit your needs.

Hope the information was quite helpful for you. Do you have any questions in mind? Feel free to comment the same down below.

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