Reverse Proxy Throughput Calculator

Estimate reverse-proxy throughput, worker CPU utilisation and maximum request rate, with the TLS termination penalty included.

Inputs

Requests per secondrps

Average response sizeKB

Worker processes or coresworkers

CPU time per requestµs

Terminating TLS at the proxy

Requests reusing an existing connection%

Throughput

6,720.0Mbps

Maximum Sustainable Request Rate

107,744rps

Worker CPU Utilisation

18.6%

Effective CPU per Request

74.3µs

New Connections per Second

2,000cps

Step by step

Values used
Requests per second = 20,000 rps; Average response size = 42 KB; Worker processes or cores = 8 workers; CPU time per request = 55 µs; Terminating TLS at the proxy = Yes; Requests reusing an existing connection = 90 %
Reverse Proxy Throughput
throughput = requests/s × response size × 8 ÷ 1000 Mbps; worker utilisation = requests/s × CPU per request ÷ workers; max rps = workers ÷ CPU per request.
Throughput
= 6,720.0 Mbps
Maximum Sustainable Request Rate
= 107,744 rps
Worker CPU Utilisation
= 18.6
Effective CPU per Request
= 74.3 µs
New Connections per Second
= 2,000 cps

How it works

A reverse proxy costs a roughly fixed amount of CPU per request plus per-byte copying, so dividing the available worker seconds by the per-request cost gives the request ceiling. TLS termination adds around a third to that cost even with hardware AES. Keepalive ratio is the hidden variable: dropping from 90% to 50% reuse triples the new-connection rate and pushes the handshake path, not the proxy CPU, into being the bottleneck.

Formula

Reverse Proxy Throughput

throughput = requests/s × response size × 8 ÷ 1000 Mbps; worker utilisation = requests/s × CPU per request ÷ workers; max rps = workers ÷ CPU per request.

effectiveCpuUs: CPU per request, multiplied by 1.35 when the proxy terminates TLS
newConnectionsPerSec: Requests that must open a fresh TCP and TLS session

Frequently Asked Questions

How is Reverse Proxy Throughput calculated?

throughput = requests/s × response size × 8 ÷ 1000 Mbps; worker utilisation = requests/s × CPU per request ÷ workers; max rps = workers ÷ CPU per request. A reverse proxy costs a roughly fixed amount of CPU per request plus per-byte copying, so dividing the available worker seconds by the per-request cost gives the request ceiling. TLS termination adds around a third to that cost even with hardware AES.

Why does Reverse Proxy Throughput matter?

Keepalive ratio is the hidden variable: dropping from 90% to 50% reuse triples the new-connection rate and pushes the handshake path, not the proxy CPU, into being the bottleneck.

What values do I need to enter?

This calculator takes 6 inputs: Requests per second, Average response size, Worker processes or cores, CPU time per request, Terminating TLS at the proxy, Requests reusing an existing connection. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

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