Calculator inputs
Use the responsive calculator grid below. Large screens show three columns, smaller screens show two, and mobile shows one.
Formula used
Aggregate Payload Bits = Payload Size per Stream × Unit Conversion × Parallel Streams
Payload Throughput = Aggregate Payload Bits ÷ Transfer Duration in Seconds
Wire Throughput = Payload Throughput ÷ (1 − Protocol Overhead)
Goodput = Payload Throughput × Utilization Factor × (1 − Retransmission)
Link Utilization = Wire Throughput ÷ Configured Link Speed × 100
This model treats your entered transfer size and time as the baseline payload flow, then adjusts it using overhead, retransmission, and usable link efficiency.
How to use this calculator
- Enter the payload amount transferred by each stream.
- Choose the payload unit that matches your measurement.
- Enter the transfer duration and its time unit.
- Set the number of parallel streams in the test.
- Add protocol overhead as a percentage of on-wire traffic.
- Enter retransmission to reflect packet retries or errors.
- Set the utilization factor for real-world link efficiency.
- Optionally add configured link speed for utilization and headroom.
- Click calculate to show results above the form.
- Use the export buttons to save CSV or PDF reports.
Example data table
| Scenario | Payload | Duration | Overhead | Retransmission | Utilization | Estimated Goodput |
|---|---|---|---|---|---|---|
| Office file transfer | 500 MB | 60 sec | 6% | 1% | 92% | 60.72 Mbps |
| Backup sync | 2 GB | 5 min | 8% | 2% | 88% | 45.97 Mbps |
| Video delivery | 3 GB | 20 min | 5% | 0.5% | 95% | 18.91 Mbps |
| WAN replication | 10 GB | 15 min | 10% | 3% | 85% | 73.29 Mbps |
Frequently asked questions
1. What does throughput mean in networking?
Throughput is the amount of data transferred over time. It shows real transport capacity during a test or production flow.
2. What is the difference between throughput and goodput?
Throughput includes transferred traffic volume. Goodput focuses on useful payload delivered after retries, inefficiency, and practical link conditions are considered.
3. Why does protocol overhead matter?
Headers, framing, acknowledgments, and encapsulation consume link capacity. Higher overhead means more wire traffic is needed to deliver the same payload.
4. Why include retransmission in the calculator?
Retransmission reflects packets resent because of drops or errors. More retries reduce effective delivery speed and waste available bandwidth.
5. What does utilization factor represent?
Utilization factor estimates how much of nominal link capacity is realistically usable after congestion, contention, protocol behavior, and device limitations.
6. Can I use this for Wi-Fi and wired links?
Yes. It works for Ethernet, Wi-Fi, WAN, VPN, and many transport paths, provided your inputs represent the actual transfer conditions.
7. Why can link utilization exceed 100%?
That result means your requested or measured wire rate is greater than the configured link speed. It signals mismatch or unrealistic inputs.
8. Which units should I choose for best accuracy?
Choose the same units used by your test logs, monitoring system, or benchmarking tool. Consistent units produce the most reliable comparison.