How to use the bandwidth calculator
- Enter the file size and the link speed.
- The tool returns transfer time, factoring in a small protocol overhead.
- Toggle between MB and MiB to match your storage / network vendor conventions.
Bandwidth Calculator
Convert bandwidth units or estimate transfer time based on bandwidth and file size.
Bandwidth Calculator
Convert bandwidth units or estimate transfer time based on bandwidth and file size.
Bandwidth (bps)—
Bandwidth (Kbps)—
Bandwidth (Mbps)—
Bandwidth (Gbps)—
Bandwidth (Tbps)—
Transfer Time—
Frequently asked questions
Why does a 100 Mbps link not transfer 100 MB per second?
Network speeds use bits while file sizes use bytes. 100 Mbps equals 12.5 MB/s in theory. Subtract protocol overhead and shared-link contention to get realistic throughput.
How does TCP overhead affect transfer time?
TCP adds roughly 3 to 5% overhead from headers, ACKs, and retransmits. Layer it with SMB or HTTPS and you're looking at another 5 to 15% on top. Practical throughput? Usually lands between 80 to 90% of your theoretical link speed.
What is the difference between throughput and bandwidth?
Bandwidth is the maximum capacity of the link. Throughput is what you actually get—the real data rate during a transfer. It's always less than bandwidth.
How long should a 10 GB transfer take on 1 Gbps?
1 Gbps = 125 MB / s ideal. 10 GB / 125 MB ≈ 80 s ideal, ~90 to 110 s realistic depending on protocol overhead and disk write speed.