Networking
Bandwidth Calculator
Estimate transfer time, required speed, or transferable data size. Everything runs locally in your browser.
Inputs
Tip: internet plans are usually advertised in Mbps (megabits per second), while file sizes are usually MB/GB (bytes).
Uses 100% efficiency by default. Show advanced to account for protocol overhead and real-world throughput.
Result
How long should this transfer take?
Transfer time
1m 20s
Assumes 100% efficiency of the advertised speed.
Seconds
80 sec
Minutes
1.33 min
Hours
0.02 hr
Quick explanation
The tool converts your inputs into bits, bytes, and seconds, then applies:
- time = (data × 8) ÷ (speed × efficiency)
- speed = (data × 8) ÷ (time × efficiency)
- data = (speed × efficiency) × time ÷ 8
Common conversions
1 byte = 8 bits.
100 Mbps (megabits/sec) ≈ 12.5 MB/s (megabytes/sec) at 100% efficiency.
Real transfers are typically slower due to protocol overhead, Wi‑Fi conditions, congestion, and server limits.
When to use which mode
- Transfer time: you know the file size and your connection speed.
- Required speed: you have a deadline and know the file size.
- Transferable data: you know speed and a time window (like overnight).
Practical tips
- If you’re on Wi‑Fi, try placing the router closer or using Ethernet for large uploads.
- ISPs often advertise download speeds; upload can be much lower.
- For video/streaming, use Mbps (bitrate), not MB/s.