Ethernet Speed Calculator
Calculate file transfer time over Ethernet, required cable category, and real-world throughput for any network speed and file size.
Ethernet is the most common wired local area network (LAN) technology, used in homes, offices, and data centers worldwide. It was developed by Robert Metcalfe and colleagues at Xerox PARC in 1973 and has evolved from the original 10 Mbps to modern 400 Gbps standards.
Ethernet Speed Standards
| Standard | Speed | Max Cable Run | Typical Use |
|---|---|---|---|
| 10BASE-T | 10 Mbps | 100 m | Legacy |
| Fast Ethernet (100BASE-T) | 100 Mbps | 100 m | Older networks |
| Gigabit Ethernet (1000BASE-T) | 1 Gbps | 100 m | Home / small office |
| 2.5GBASE-T | 2.5 Gbps | 100 m | Wi-Fi 6 uplink |
| 5GBASE-T | 5 Gbps | 100 m | High-performance |
| 10GBASE-T | 10 Gbps | 100 m | Server connections |
| 25GbE | 25 Gbps | 30 m (direct attach) | Data center |
| 40GbE | 40 Gbps | Data center | Aggregation |
| 100GbE | 100 Gbps | Data center | Backbone |
Cable Categories
| Cable | Max Speed | Frequency | Notes |
|---|---|---|---|
| Cat 5 | 100 Mbps | 100 MHz | Obsolete |
| Cat 5e | 1 Gbps | 100 MHz | Common home cable |
| Cat 6 | 1 Gbps (100 m) / 10 Gbps (55 m) | 250 MHz | Good choice today |
| Cat 6A | 10 Gbps | 500 MHz | Best for 10GbE runs |
| Cat 7 | 10 Gbps | 600 MHz | Shielded, niche use |
| Cat 8 | 25–40 Gbps | 2000 MHz | Data center only |
Transfer Time Formula
Transfer time (seconds) = File size (bits) ÷ Link speed (bits/second)
Remember: storage uses bytes (B), networking uses bits (b). 1 byte = 8 bits.
Overhead Factor
Real-world Ethernet throughput is typically 80–95% of the theoretical maximum due to protocol overhead (headers, acknowledgments, error correction). This calculator uses a 90% efficiency factor.
Bits vs Bytes
- 1 KB = 1,024 bytes = 8,192 bits
- 1 MB = 1,048,576 bytes = 8,388,608 bits
- 1 GB = 1,073,741,824 bytes ≈ 8.59 billion bits