Quettabytes (QB) to Gigabytes (GB) Converter
Convert quettabytes to gigabytes.
1 QB = 1e21 GB
How to convert QB to GB
File sizes here use the decimal (SI) system, the same one drive makers and network providers use. In that system 1 Quettabyte is 1030 bytes and 1 Gigabyte is 109 bytes. Divide one by the other and you get the ratio between the two units: 1030 ÷ 109 = 1021.
Quettabyte is the bigger unit, so you multiply. Every QB holds 1021 GB, which means the decimal point moves 21 places to the right.
On the ladder (B → KB → MB → GB → TB → PB → EB → ZB → YB → RB → QB) these two are 7 steps apart. Every step is a factor of 1,000, so 7 steps means 1,000 multiplied by itself 7 times, which is 1021.
The formula
GB = QB × 10211 QB = 1 × 1021 GB1021 means 1 followed by 21 zeros
Worked example 1: Converting 1 QB
1 QB × 1021 = 1 × 1021 GBThe decimal point moves 21 places to the right.
The quettabyte is the largest SI-prefixed byte unit, and nothing stores data at that scale.
Worked example 2: Converting 0.5 QB
0.5 QB × 1021 = 5 × 1020 GBThe decimal point moves 21 places to the right.
Worked example 3: Converting 12.75 QB
12.75 QB × 1021 = 1.275 × 1022 GBThe decimal point moves 21 places to the right.
Need the other direction? Open the GB to QB converter.
QB to GB examples
The quettabyte is the largest SI-prefixed byte unit, and nothing stores data at that scale. In gigabytes that is 1 × 1021 GB.
| QB | GB |
|---|---|
| 1 QB | 1 × 1021 GB |
| 2.5 QB | 2.5 × 1021 GB |
| 10 QB | 1 × 1022 GB |
| 50 QB | 5 × 1022 GB |
| 100 QB | 1 × 1023 GB |
| 500 QB | 5 × 1023 GB |
| 1,000 QB | 1 × 1024 GB |
Where QB to GB comes up
Quetta- is the SI prefix for 1030, also adopted in 2022, so a quettabyte is 1,000 ronnabytes. Quettabytes are the top of the official SI ladder. They turn up in unit tables and in explanations of the newest prefixes.
A gigabyte is 1,000 megabytes, about 250 photos at 4 MB each. Gigabytes are the language of phone storage, RAM, mobile data plans, game installs and USB sticks.
Going from quettabytes down to gigabytes always gives a bigger number, because the unit you land on is smaller. It is the usual direction when a limit or a form asks for a smaller unit than the one you have in mind.
QB to GB FAQ
How many gigabytes are in 1 quettabyte?
There are 1021 gigabytes in 1 quettabyte, so 1 QB = 1021 GB.
Is QB to GB decimal or binary?
This page is decimal (SI), where 1 KB = 1,000 B. Operating systems often count in powers of 1,024 and still print KB, MB or GB, when they really mean KiB, MiB and GiB. At QB the gap is wider still.
How do I convert GB to QB?
Go the other way: divide by 1021, which moves the decimal point 21 places to the left. The swap button on the converter does it for you.