Bandwidth-Delay Product Calculator
Enter link bandwidth and round-trip time to calculate how much data fills the network pipe and get TCP send/receive buffer size recommendations.
Link Parameters
RTT = round-trip time (use for TCP). One-way is doubled internally.
Bandwidth-Delay Product
Enter bandwidth and latency to calculate BDP
BDP (bytes)
Bits
Bytes
Kilobytes (KB)
Megabytes (MB)
TCP Buffer Recommendations
Results appear after calculation above.
1× BDP (minimum)
2× BDP (recommended)
4× BDP (high-jitter)
Linux sysctl (2× BDP)
These are socket-level minimums. Linux auto-tuning (tcp_rmem/tcp_wmem) also needs its max value raised to at least the recommended buffer size.
Pipe Fill Ratio
How full the network pipe is with the current TCP window vs. BDP
Common TCP default window sizes shown for comparison. A ratio <100% means the link is under-utilized.
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Summary
Enter link bandwidth and round-trip time to calculate how much data fills the network pipe and get TCP send/receive buffer size recommendations.
How it works
- Enter the link bandwidth (bits per second) — use the unit selector for Kbps, Mbps, or Gbps.
- Enter the one-way latency or round-trip time (RTT) in milliseconds.
- Choose whether you entered one-way latency or RTT — the calculator converts automatically.
- The BDP appears instantly in bits, bytes, kilobytes, and megabytes.
- Check the TCP buffer recommendation section to see the minimum socket buffer size needed.
- Use the presets for common link types (LAN, WAN, satellite, etc.) as starting points.
Use cases
- Size TCP socket buffers for high-throughput WAN or intercontinental links.
- Estimate in-flight data for network capacity planning.
- Debug slow file transfers over long-distance links.
- Verify that TCP window size matches the pipe capacity.
- Teaching networking concepts like pipe-filling and buffer bloat.
- Compare link efficiency across different bandwidth and latency combinations.
Frequently Asked Questions
Last updated: 2026-06-11 ·
Reviewed by Nham Vu