When to use this calculator
Estimate a simple transport window and RTT throughput ceiling. Window-limited upper estimate; congestion control, loss, protocol overhead and link rate can lower throughput.
Explore the networks & service capacity calculators for other questions in this topic. For a related calculation, use the Upload Time Calculator: Estimate the time required to upload a decimal-megabyte file.
PUTTING IT INTO PRACTICE
TCP Window Throughput: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Effective window (bytes) | 250,000 |
| Round-trip time (ms) | 20 |
| Result | 100 Mbps |
- Check the input labels and enter the example values above.
- Apply the relationship: Ideal Mbps ≈ window bytes × 8/(RTT seconds)/1,000,000.
- The result is 100 Mbps, rounded for display.
How to interpret your result
Window-limited upper estimate; congestion control, loss, protocol overhead and link rate can lower throughput.
Bits and bytes differ by eight. Average request rate can hide peaks and concurrency. A packet’s serialization delay is only one part of end-to-end network latency.
Frequently asked questions
Does serialization delay equal network latency?
No. Propagation, queuing, processing, framing and other paths can add to total latency.
When is the tcp window throughput calculator useful?
Estimate a simple transport window and RTT throughput ceiling. Window-limited upper estimate; congestion control, loss, protocol overhead and link rate can lower throughput.
How do I use the tcp window throughput calculator?
Enter effective window (bytes), round-trip time (ms). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Ideal Mbps ≈ window bytes × 8/(RTT seconds)/1,000,000.
What should I check before using the result?
Window-limited upper estimate; congestion control, loss, protocol overhead and link rate can lower throughput.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Calculators Map editorial process · Updated · Methods and limitations