Calculate File Sizes
SI · Binary · All Units
Convert between bytes, kilobytes, megabytes, gigabytes, terabytes and more. Supports both decimal (SI) and binary (IEC) systems.
All Conversions
1,000,000,000
1,000,000
1,000
1
0.001
1.0000e-6
Quick Conversions
Why Use Our File Size Calculator
Master data units with precision
Both Systems
Full support for decimal (SI) and binary (IEC) unit standards
Auto-Conversion
See all equivalent unit values calculated simultaneously
All Units
From bytes through petabytes in both decimal and binary systems
High Precision
Accurate calculations to multiple decimal places for any value
Storage Planning
Calculate exactly how much storage space your project needs
Bandwidth Calc
Determine transfer times and bandwidth requirements for any file
Complete Guide: How to Use the File Size Calculator
Convert file sizes between bytes, KB, MB, GB, and TB instantly. Our calculator supports both binary (KiB = 1024 bytes) and decimal (KB = 1000 bytes) standards, making it essential for developers, system administrators, and anyone working with storage capacity.
Step-by-Step Instructions
- 1
Enter a file size
Type the size value in the input field. Supports integers and decimals (e.g., 1.5, 2048, 0.75).
- 2
Select the source unit
Choose the unit you're converting from: bytes, KB, MB, GB, TB, or their binary equivalents (KiB, MiB, GiB, TiB).
- 3
View all conversions
The tool instantly shows the equivalent value in all other units — both binary and decimal — so you can compare at a glance.
- 4
Copy any value
Click on any converted value to copy it. Useful for documentation, specs, or configuration files.
Common Use Cases
- ✓Server planning — calculate storage requirements in the right unit for cloud provider pricing
- ✓Development — convert between units for file upload limits, buffer sizes, and API payload limits
- ✓Networking — understand bandwidth specifications (Mbps vs MBps) and data transfer volumes
- ✓Storage — compare drive capacities using the correct binary vs decimal standard
- ✓Content delivery — estimate CDN bandwidth costs based on file sizes and traffic
- ✓Documentation — express file sizes in human-readable formats for user-facing messages
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Frequently Asked Questions
What is the difference between MB and MiB?
MB (megabyte) uses the decimal system: 1 MB = 1,000 KB = 1,000,000 bytes. MiB (mebibyte) uses the binary system: 1 MiB = 1,024 KiB = 1,048,576 bytes. Storage manufacturers use MB, while operating systems often use MiB.
Why does my hard drive show less space than advertised?
Hard drive manufacturers use decimal units (1 GB = 1,000,000,000 bytes), while your OS reports in binary units (1 GiB = 1,073,741,824 bytes). A 500 GB drive shows about 465 GiB in your OS.
How many MB in a GB?
In decimal (SI): 1 GB = 1,000 MB. In binary (IEC): 1 GiB = 1,024 MiB. This tool supports both systems.
What unit is used for internet speed?
Internet speeds are typically measured in Mbps (megabits per second), not MBps (megabytes per second). 1 byte = 8 bits, so 100 Mbps ≈ 12.5 MBps.
What is the largest file size unit?
Common units go up to TB (terabyte) and PB (petabyte). Beyond that are exabytes (EB), zettabytes (ZB) and yottabytes (YB). This tool covers bytes through petabytes.