Estimate the traffic and ranking impact of a site migration’s redirects.
Migrations almost always cause a temporary dip that recovers over one to three months. Permanent loss comes only from URLs that were never mapped, which is why a complete redirect map matters more than anything else. The cumulative loss during recovery is usually the acceptable cost; unmapped URLs are the avoidable one.
Redirect Impact
Permanent loss ≈ traffic × unmapped URL share; cumulative loss integrates the recovery curve
Permanent loss ≈ traffic × unmapped URL share; cumulative loss integrates the recovery curve Migrations almost always cause a temporary dip that recovers over one to three months. Permanent loss comes only from URLs that were never mapped, which is why a complete redirect map matters more than anything else.
The cumulative loss during recovery is usually the acceptable cost; unmapped URLs are the avoidable one.
This calculator takes 4 inputs: Current monthly organic traffic, Share of URLs redirected correctly, Expected temporary traffic loss, Expected recovery period. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.