USB Speed Converter
Compare data transfer speeds across USB 2.0, 3.0, 3.1, 3.2, and USB4 standards.
See theoretical and real-world speeds in MB/s and Gbps.
Select a USB standard or enter a speed to convert between Gbps and MB/s.
Understanding USB Speed Standards
USB (Universal Serial Bus) has evolved through multiple generations, each dramatically increasing data transfer speeds. The naming has become confusing because the USB Implementers Forum has renamed standards multiple times. For example, what was originally called “USB 3.0” was later renamed to “USB 3.1 Gen 1” and then again to “USB 3.2 Gen 1.” This converter helps cut through the confusion.
USB Speed Standards:
| Standard | Marketing Name | Max Speed (Gbps) | Max Speed (MB/s) | Year |
|---|---|---|---|---|
| USB 1.0 | Low Speed | 0.0015 | 0.19 | 1996 |
| USB 1.1 | Full Speed | 0.012 | 1.5 | 1998 |
| USB 2.0 | Hi-Speed | 0.48 | 60 | 2000 |
| USB 3.0 / 3.2 Gen 1 | SuperSpeed | 5 | 625 | 2008 |
| USB 3.1 / 3.2 Gen 2 | SuperSpeed+ | 10 | 1,250 | 2013 |
| USB 3.2 Gen 2x2 | SuperSpeed 20Gbps | 20 | 2,500 | 2017 |
| USB4 Gen 2x2 | USB4 20Gbps | 20 | 2,500 | 2019 |
| USB4 Gen 3x2 | USB4 40Gbps | 40 | 5,000 | 2019 |
| USB4 Version 2.0 | USB4 80Gbps | 80 | 10,000 | 2022 |
Theoretical vs Real-World Speeds:
The speeds listed above are theoretical maximums. Real-world speeds are typically 50-80% of the theoretical maximum due to protocol overhead, encoding schemes, and controller limitations.
| Standard | Theoretical | Typical Real-World |
|---|---|---|
| USB 2.0 | 60 MB/s | 25-35 MB/s |
| USB 3.2 Gen 1 (USB 3.0) | 625 MB/s | 300-400 MB/s |
| USB 3.2 Gen 2 (USB 3.1) | 1,250 MB/s | 700-1,000 MB/s |
| USB 3.2 Gen 2x2 | 2,500 MB/s | 1,500-2,000 MB/s |
| USB4 40Gbps | 5,000 MB/s | 3,000-4,000 MB/s |
Speed Unit Conversions:
1 Gbps (gigabit per second) = 125 MB/s (megabytes per second)
1 MB/s = 0.008 Gbps
1 byte = 8 bits
This is because network and bus speeds are measured in bits, while file transfer speeds are measured in bytes. Always divide the bit rate by 8 to get the byte rate.
Connector Types:
USB speed is determined by both the controller and the cable, not just the connector shape:
- USB-A: Found on all standards from 1.0 to 3.2 Gen 2. Blue interior usually indicates USB 3.0+.
- USB-B: Common on printers and older devices. Square shape.
- Micro-USB: Common on older phones and devices. USB 2.0 speeds.
- USB-C: The modern universal connector. Supports all speeds from USB 2.0 to USB4. The connector shape alone does NOT guarantee high speed — a USB-C port can be wired for USB 2.0 speeds.
Practical File Transfer Times:
Time to transfer a 10 GB file:
| Standard | Theoretical Time | Real-World Time |
|---|---|---|
| USB 2.0 | 2 min 47 sec | 5-7 min |
| USB 3.2 Gen 1 | 16 sec | 25-33 sec |
| USB 3.2 Gen 2 | 8 sec | 10-14 sec |
| USB4 40Gbps | 2 sec | 2.5-3.3 sec |