About Bandwidth Calculator

Calculates file transfer time from file size and connection speed, then compares the result across nine connection types—from 56 Kbps dial-up to 10 Gbps Ethernet. File sizes use binary units (1 KB = 1,024 bytes) while network speeds use decimal (1 Mbps = 1,000,000 bits/sec), matching how operating systems and ISPs actually measure each. A reference tab lists bandwidth requirements for streaming, video conferencing, gaming, and general browsing.

• File size input in B, KB, MB, GB, or TB (binary, 1024-based); speed input in bps, Kbps, Mbps, Gbps, or Tbps (decimal, 1000-based)
• Transfer time formula: (file size in bytes × 8) ÷ speed in bits per second, displayed in human-readable hours/minutes/seconds
• Connection comparison table shows transfer time across 9 types: Dial-up (56 Kbps), DSL (25 Mbps), Cable (100 Mbps), Fiber (1 Gbps), 4G (50 Mbps), 5G (1 Gbps), Wi-Fi 5 (866 Mbps), Wi-Fi 6 (2.4 Gbps), 10GbE (10 Gbps)
• Reference guide with real-world bandwidth needs: SD streaming 3–4 Mbps, HD 5–8 Mbps, 4K 25–35 Mbps

Frequently Asked Questions

Why are file sizes and network speeds measured differently?

Historical convention. Storage has used binary prefixes (1 KB = 1,024 bytes) since the early days of computing, while networking has always used decimal (1 Mbps = 1,000,000 bits/sec). This tool matches those real-world conventions so the numbers make sense when compared to your OS file sizes and ISP speed tests.

Does it account for protocol overhead?

No. The calculation gives you raw theoretical transfer time. Real-world transfers include TCP/IP overhead, encryption (TLS), and application-layer framing that typically add 5–15% to actual transfer time. Treat the result as an optimistic baseline.