diff --git a/ent/admn/dimension.go b/ent/admn/dimension.go
new file mode 100644
index 0000000..12d7371
--- /dev/null
+++ b/ent/admn/dimension.go
@@ -0,0 +1,22 @@
+package admn
+
+import (
+	"sourcecode.social/reiver/go-opt"
+)
+
+// Dimension represents a Mastodon API "Admin::Dimension".
+//
+// See:
+// https://docs.joinmastodon.org/entities/Admin_Dimension/
+type Dimension struct {
+	Key    opt.Optional[string] `json:"key"`
+	Data []DimensionData        `json:"data"`
+}
+
+type DimensionData struct {
+	Key        opt.Optional[string] `json:"key"`
+	HumanKey   opt.Optional[string] `json:"human_key"`
+	Value      opt.Optional[string] `json:"value"`
+	Unit       opt.Optional[string] `json:"unit"`
+	HumanValue opt.Optional[string] `json:"human_value"`
+}