Iteration Calculator

What is the Iteration Calculator?

The Iteration Calculator estimates how many times each virtual user will run your test script per hour, and the total for all users combined. An iteration is one full pass through the script, for example log in → search → add to cart → log out. Knowing the iteration count helps you check that the test matches the business volume you are modelling.

How it works

Each iteration takes response time + pacing + think time seconds to complete. Dividing an hour by that per-iteration time gives how many iterations one user runs per hour; multiplying by the number of users gives the total across the whole test.

Formula to calculate iterations per hour

Where:

• 3600 — Number of seconds in one hour.
• Response Time — End-to-end time to complete one iteration, in seconds.
• Pacing — Delay between two iterations, in seconds (0 if none).
• Think Time — Sum of all think times in the script, in seconds (0 if none).
• Users — Number of concurrent virtual users (threads).

Example of iteration calculation

A search-and-browse script runs with 25 users.

Inputs

• Users = 25
• Response Time = 10 seconds
• Pacing = 5 seconds
• Think Time = 5 seconds

Step-by-step

1. Time per iteration = 10 + 5 + 5 = 20 seconds
2. Iterations per Hour (per user) = 3600 ÷ 20 = 180
3. Total Iterations per Hour = 180 × 25 = 4500

Common mistakes to avoid

• Ignoring pacing and think time, which inflates the estimated iteration count well above what the test will actually produce.

• Using response time from a lightly-loaded baseline instead of the response time expected under target load.

• Comparing total iterations across tests with different user counts without checking the per-user rate too.