- 316,448 inhabitants (2026)
- 3,728.3 km² area
Hierarchy
Child units
Fredrikstad/Sarpsborg
Settlement
Fredrikstad
Municipality
Sarpsborg
Municipality
Moss
Municipality
Indre Østfold
Municipality
Halden
Municipality
Rakkestad
Municipality
Råde
Municipality
Våler
Municipality
Hvaler
Municipality
Skiptvet
Municipality
Ryggebyen
Settlement
Marker
Municipality
Spetalen
Settlement
Aremark
Municipality
Skivika
Settlement