Back-of-the-Envelope Scale & Capacity Calculator

Interactive estimation engine for QPS, daily/yearly storage volume, and 80/20 RAM cache sizing.

Staff Architect Estimation Engine

Back-of-the-Envelope Capacity & Scale Calculator

Scale: 50M DAU
Daily Active Users (DAU):50 Million
Reads / User / Day:40 Reads
Writes / User / Day:4 Writes
Item Payload Size:2 KB
Peak Read QPS (2.5x):
57,870 QPS

Avg: 23,148 QPS

Peak Write QPS (2.5x):
5,788 QPS

Avg: 2,315 QPS

Yearly Storage:
135.8 TB / Year

+381 GB / Day

80/20 RAM Cache Size:
763 GB RAM

20% of daily read data