🧮 PERFTRACTOR
🌐 Network Bandwidth Calculator
Estimate the network throughput your test will consume.
🌐 Network Bandwidth Calculator
Estimate the network throughput your test will consume.
Mbps required
The Formula
Mbps = VU × TPS × (Request + Response KB) × 8 ÷ 1024 × (1 + Overhead)
- VU = Concurrent virtual users
- TPS = Transactions per second per user
- Request/Response KB = Average payload sizes
- Overhead = Protocol overhead (TCP/TLS headers, retransmits)
How it works
Load tests can saturate the network link of the load generator or the corporate VPN long before the target system feels any pressure. Estimating bandwidth up front prevents a whole class of misleading results.
Total throughput = concurrent users × transactions per second × average bytes per transaction (request + response), converted to megabits and inflated by protocol overhead (TCP/TLS headers, retransmissions, typically 15–25%).
If the result approaches your link capacity, distribute the load across multiple generators in different networks, or move generation into the same data center or cloud region as the target.
Frequently Asked Questions
How much bandwidth does a load test need?
Bandwidth (Mbps) = concurrent users × TPS per user × (request + response size in KB) × 8 ÷ 1024 × (1 + protocol overhead). 100 users at 2 TPS each moving 55 KB per transaction needs roughly 103 Mbps with 20% overhead.
Why do my load test results look worse when running from my laptop?
Local links, VPNs, and Wi-Fi add latency and cap throughput. If the generator-side network saturates, response times inflate regardless of server health. Estimate bandwidth first and generate load from a data center or cloud region near the target.
What protocol overhead should I assume for HTTP tests?
Plan for 15–25% overhead for TCP/TLS headers, connection setup, and retransmissions. Use the higher end for TLS-heavy APIs with small payloads, the lower end for large responses on kept-alive connections.