Packet Loss Throughput Calculator
Use this packet loss throughput calculator to see why even small packet loss can sharply reduce TCP transfer rates on higher-latency paths.
Calculator
How to use this calculator
Enter the planning values that match your network, storage, or cloud scenario. Use realistic production assumptions when sizing anything that affects availability, performance, or cost.
Formula or calculation method
The calculator uses a common TCP throughput approximation based on MSS, round-trip time, and packet loss, then caps the estimate at the link speed.
Worked example
On a 1 Gbps path with 60 ms RTT, 0.1% packet loss can reduce a single TCP flow far below the link rate.
Practical planning tips
- WAN troubleshooting.
- Explaining slow backups.
- Comparing latency and packet loss scenarios.
Common mistakes to avoid
- Ignoring packet loss because the percentage looks small.
- Comparing single-flow TCP to multi-stream tools.
- Using this as a substitute for packet captures and monitoring.
Frequently asked questions
Why does 0% loss show link speed?
With no packet loss entered, the loss formula does not limit throughput, so the link speed is used as the cap.
Is this exact?
No. TCP implementations, congestion control, buffering, and application behavior also matter.