Bandwidth Calculator

Calculate file download/upload times and convert between bandwidth and data units.

Result

Fill in the fields above, then press Calculate.

A bandwidth calculator estimates file download times and converts between data transfer rate units like Mbps, MB/s, and GB/hr.

Enter the file size and select its unit, then enter your transfer speed and select the speed unit. The calculator shows the estimated download/upload time and compares across common connection speeds.

Examples

1 GB file at 100 Mbps

1 GB = 8,589,934,592 bits. 100 Mbps = 100,000,000 bps. Time = 85.9 seconds (1 min 26 sec).

4 GB movie at 50 Mbps

Time = approximately 5 min 43 sec.

Frequently Asked Questions

Why is my actual download slower than calculated?
Real-world speeds are affected by protocol overhead (TCP/HTTP headers), network congestion, server throttling, and the difference between advertised and actual speeds. Expect 70-90% of theoretical speed.
What is the difference between Mbps and MBps?
Mbps (megabits per second) measures network speed. MBps (megabytes per second) measures file transfer rates. 1 MBps = 8 Mbps. ISPs advertise in Mbps; file managers show MBps.
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Quick Tips

  • •To roughly convert Mbps to MB/s, divide by 8 — a 100 Mbps connection transfers about 12.5 MB per second.
  • •Test your actual speed at a site like fast.com before relying on your ISP advertised rate.
  • •For large backups, consider overnight scheduling when network congestion is lowest.