Rule of thumb:
- 1 GB ≈ 4,000 km² of Sentinel-2 imagery
- 1 GB ≈ 4,000 km² of Sentinel-1 imagery
- 1 GB ≈ 10,000 km² of Landsat 8/9 imagery
So the Free plan's 10 GB mosaic quota is enough for roughly 40,000 km² of Sentinel-1/-2 imagery (about the size of Switzerland) or 100,000 km² of Landsat (about the size of Iceland). Pro's 200 GB storage extends that to roughly 800,000 km² of Sentinel or 2,000,000 km² of Landsat. Enterprise storage is sized to your needs.