How to Size Infrastructure Before a Load Test

Before you run load tests, estimate infrastructure requirements to avoid false negatives caused by under-provisioning.

Simple Sizing Flow

1. Estimate target RPS for the scenario.
2. Determine per-instance safe throughput.
3. Add safety margin (20% to 40% is common).
4. Validate burst behavior separately.

Instance Estimate

instances_min = ceil(target_rps / per_instance_rps)
instances_recommended = ceil(instances_min * (1 + safety_margin_percent/100))

Checklist Before Test Day

• Autoscaling thresholds configured and tested.
• Database pool limits reviewed.
• Upstream/downstream dependencies benchmarked.
• Error budget and rollback criteria defined.

Practical Tools

Start with Infrastructure Sizing Calculator, then validate edge cases with Burst Traffic Calculator.