In capacity planning without specific data, a common rule of thumb for 'Peak Load' vs 'Average Load' ratio is:

In most consumer-facing systems, user activity follows a 'diurnal' pattern: highly active during the day and quiet at night. Because of this, the 'Peak Load' (the busiest hour of the day) is typically 2 to 4 times higher than the yearly average. When performing back-of-the-envelope capacity planning, an engineer must always multiply their average traffic estimates by this 'Peak Factor' to ensure the system doesn't crash during busy periods. However, for extreme events like Black Friday or a viral tweet, this ratio can jump to 10x or 100x, requiring 'Auto-Scaling' infrastructure to dynamically add capacity as needed.