File Size Calculator
Convert file sizes between bytes, kilobytes, megabytes, gigabytes and terabytes quickly and accurately.
Choose decimal or binary units depending on whether you are working with storage specifications, file sizes, memory or computing data.
Convert File Size
Enter a value, choose the unit system and calculate equivalent sizes.
File Size Conversion Results
File Size Summary
Input Size
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Bytes
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Megabytes
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Gigabytes
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Decimal vs. Binary File Size Units
File sizes can be represented using either decimal or binary units. The two systems use different numbers of bytes for each unit.
| Unit | Decimal Value | Binary Equivalent |
|---|---|---|
| KB / KiB | 1,000 bytes | 1,024 bytes |
| MB / MiB | 1,000,000 bytes | 1,048,576 bytes |
| GB / GiB | 1,000,000,000 bytes | 1,073,741,824 bytes |
| TB / TiB | 1,000,000,000,000 bytes | 1,099,511,627,776 bytes |
How File Size Conversion Works
The calculator first converts the entered value into bytes. It then divides the byte value by the appropriate unit size to calculate the equivalent measurements.
Decimal Units
Decimal units use powers of 1,000. For example, 1 GB equals 1,000 MB and 1,000,000,000 bytes.
Binary Units
Binary units use powers of 1,024. For example, 1 GiB equals 1,024 MiB and 1,073,741,824 bytes.
1 byte = 8 bits
Decimal: 1 GB = 1,000,000,000 bytes
Binary: 1 GiB = 1,073,741,824 bytes
File Size Conversion Example
Suppose you have a file that is 5 GB using decimal units.
Because 1 GB equals 1,000 MB, the file is 5,000 MB.
In bytes, the same file contains 5,000,000,000 bytes.
If the same number of bytes is expressed as binary gibibytes, the value is approximately 4.66 GiB.
Common Uses for a File Size Calculator
File size conversions are useful when comparing storage capacity, checking download requirements, estimating backup sizes or understanding the size of digital files.
| Use Case | Useful Conversion |
|---|---|
| Hard Drive or SSD Storage | GB to TB |
| Large Video Files | GB to MB |
| Documents and Images | KB to MB |
| Computer Memory | MiB to GiB |
| Backup Planning | GB or TB conversions |
Frequently Asked Questions
How many MB are in 1 GB?
Using decimal units, 1 GB equals 1,000 MB. Using binary units, 1 GiB equals 1,024 MiB.
Is 1 GB the same as 1 GiB?
No. A decimal GB contains 1,000,000,000 bytes, while a binary GiB contains 1,073,741,824 bytes.
Why does my storage drive show less space than advertised?
Storage manufacturers generally use decimal units, while some operating systems may display storage using binary-based values or different unit labels. Formatting and system overhead can also affect the available capacity.
How many bytes are in 1 MB?
In decimal units, 1 MB equals 1,000,000 bytes. In binary units, 1 MiB equals 1,048,576 bytes.
How many bytes are in 1 GB?
A decimal GB contains 1,000,000,000 bytes. A binary GiB contains 1,073,741,824 bytes.
What is the difference between MB and Mb?
MB means megabytes, while Mb means megabits. One byte contains eight bits, so these units should not be treated as interchangeable.