# GiB vs GB: what is the difference?

A GiB (gibibyte) is 1,073,741,824 bytes, which is 2 to the 30th power. A GB
(gigabyte) is 1,000,000,000 bytes. A GiB is about 7.4% larger than a GB.

**Runtime prices memory per GiB, and it states the unit. The rate is
$0.0075 per reserved GiB-hour. A GiB is 1,073,741,824 bytes, not a
decimal GB** ([pricing](/docs/pricing)). A 4 GiB sandbox has 4,096 MiB of
memory. That is the value that `memoryMiB: 4096` requests.

## Why it matters when you compare prices

Cloud price lists mix the two units. A rate per GB and a rate per GiB are not
the same rate. Sandbox providers are no different. Some quote memory per
GiB-hour, and others quote it per GB-hour. A "4 GB" machine may hold either
4 billion bytes or 4 GiB. A per-GB price looks about 7% cheaper than the same
money per GiB. Before you compare two rates, convert them to the same unit.

The difference grows with the prefix. A KiB is 2.4% larger than a kB. A MiB is
4.9% larger than an MB. A GiB is 7.4% larger than a GB. A TiB is 10.0% larger
than a TB.

## The units in facts

| Unit          | Bytes         | Defined as                                         |
| ------------- | ------------- | -------------------------------------------------- |
| GB, gigabyte  | 1,000,000,000 | 10^9, an SI decimal prefix                         |
| GiB, gibibyte | 1,073,741,824 | 2^30, an IEC binary prefix                         |
| MiB, mebibyte | 1,048,576     | 2^20; 1,024 MiB make 1 GiB                         |
| KiB, kibibyte | 1,024         | 2^10                                               |
| Adopted       | December 1998 | The IEC approved the binary prefixes as a standard |

NIST notes that the binary prefixes are not part of the SI. NIST also notes
that "kilo" once meant 1,024 in computing. That usage caused the confusion the
IEC prefixes were created to end.

## Which unit Runtime uses where

| What                      | Unit       | Rate or limit                                                     |
| ------------------------- | ---------- | ----------------------------------------------------------------- |
| Memory                    | GiB        | $0.0075 per GiB-hour while running                        |
| Sizes in the API          | MiB        | `memoryMiB` and `diskMiB`, default 4096 each                      |
| Paused storage, snapshots | Decimal GB | $0.08 per GB per 30-day month                   |
| Snapshots, per hour       | GiB        | 119 microdollars per GiB-hour, the same rate |
| Volumes                   | GiB        | 153 microdollars per GiB-hour                  |
| Command output in JSON    | KiB        | At most 64 KiB (65,536 bytes) each of stdout, stderr              |

The snapshot line shows the conversion. $0.08 per decimal GB
for a 720-hour month, multiplied by 1.073741824 GB per GiB, is $0.0001193 per
GiB-hour. The price list rounds this down to 119
microdollars ([snapshots, images and volumes](/docs/pricing#snapshots-images-and-volumes)).

## Convert in code

```ts
const GIB = 2 ** 30;
const GB = 1e9;
const perGbHour = 0.0212; // a price quoted per GB-hour
console.log((perGbHour * GIB) / GB); // 0.02276..., the same price per GiB-hour
```

```python
GIB, GB = 2**30, 10**9
per_gb_hour = 0.0212  # a price quoted per GB-hour
print(per_gb_hour * GIB / GB)  # 0.02276..., the same price per GiB-hour
```

The example rate is Vercel Sandbox's published memory rate in `iad1`. It is
$0.0212 per provisioned GB-hour, checked 25 October 2026
([published rate comparison](/docs/pricing#published-rate-comparison)).

## Related

- [Pricing](/docs/pricing)
- [What is a CPU floor?](/glossary/cpu-floor)
- [Sandbox cost calculator](/calculators/sandbox-cost-calculator)
- [Vercel Sandbox pricing calculator](/calculators/vercel-sandbox-pricing-calculator)

## Sources

- [NIST: prefixes for binary multiples](https://physics.nist.gov/cuu/Units/binary.html), read 25 October 2026

Facts on this page were checked on 25 October 2026.