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.
Convert bandwidth units or estimate transfer time based on bandwidth and file size.
Convert bandwidth units or estimate transfer time based on bandwidth and file size.
Network speeds use bits while file sizes use bytes. 100 Mbps = 12.5 MB / s in theory. Subtract protocol overhead and shared-link contention to get realistic throughput.
TCP adds ~3 to 5 % overhead from headers, ACKs and retransmits. For SMB or HTTPS add another 5 to 15 %. Practical throughput is usually 80 to 90 % of theoretical link speed.
Bandwidth is the maximum capacity of the link. Throughput is the actual data rate observed during a transfer, always less than bandwidth.
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.