Server Sizing Calculator

Calculate CPU, RAM, storage, and instance count from workload requirements.

Concurrent users

Requests per user per min

Avg response time (ms)

Target CPU utilization %

Memory per connection (MB)

App base memory (MB)

Storage per user (GB)

Total registered users

Tab to move between fields

Recommended vCPUs

Recommended RAM (GB)

Instances needed (HA)

Total storage (GB)520

Total requests/sec16.67

Concurrent requests3.3

Est. bandwidth (Mbps)6.51

Peak vCPUs (2x traffic)2

How to Use This Calculator

Enter Concurrent Users, Requests per User per Minute, and Average Response Time (ms).
Set Target CPU Utilization % to leave headroom for traffic spikes.
Input Memory per Connection (MB) and App Base Memory (MB) to size RAM.
Enter Storage per User (GB) and Total Registered Users.
Review Recommended vCPUs, RAM (GB), and Storage (GB) to select the right server or cloud instance.

What each input means

Concurrent users: Maximum simultaneous active users on the system.
Requests per user per min: Average API/page requests each active user generates per minute.
Avg response time (ms): Average server-side response time in milliseconds.
Target CPU utilization %: Target CPU utilization ceiling (70% is typical for production).
Memory per connection (MB): Memory consumed per active user connection/session.
App base memory (MB): Fixed memory used by the application (JVM heap, runtime, caches).
Storage per user (GB): Average disk storage per registered user (uploads, data).
Total registered users: Total user accounts (for storage calculation).

Recommended vCPUs: Total vCPUs needed across all instances.
Recommended RAM (GB): Total RAM needed with 20% buffer.
Instances needed (HA): Number of server instances for high availability (minimum 2).
Total storage (GB): Disk storage for application data + OS.
Total requests/sec: Calculated requests per second at given load.
Concurrent requests: Average number of in-flight requests at any moment.
Est. bandwidth (Mbps): Estimated network bandwidth assuming ~50KB avg response.
Peak vCPUs (2x traffic): vCPUs needed to handle double the normal traffic.

Identify Input Parameters
4 parameters
Concurrent users = 500, Requests per user per min = 2, Avg response time (ms) = 200, Target CPU utilization % = 70 = 8 input(s) provided
Calculate Recommended vCPUs
Recommended vCPUs = max(1
1 = 1
Calculate Recommended RAM
Recommended RAM = max(1
2 = 2
Calculate Instances needed
Instances needed
2 = 2
Calculate Total storage
Total storage
520 = 520
Calculate Total requests/sec
Total requests/sec = (concurrentUsers * avgRequestsPerUserPerMin) / 60
16.67 = 16.67