Sonic
* Out of the Hedgehog triplets, Sonic is the eldest.
* Amy is 3 years younger than Sonic.
* Blaze is a year younger than Sonic.
* Tangle, Lilac, and Surge are the same age as Sonic.
* Sally is a year older than Sonic.
Tails
* Tails is 4 years younger than Sonic.
* Cream is 2 years younger than Tails.
* Marine is a year younger than Tails.
* Whisper is 3 years older than Tails.
* Milla is 2 years older than Tails.
* Cosmo and Zooey are same age as Tails.
Knuckles
* Knuckles is a year older than Sonic.
* Shade is a year younger than Knuckles.
* Rouge is 2 years older than Knuckles.
* Jewel is the same age as Knuckles.
* Carol is 3 years younger than Knuckles.
* Tikal is a year younger than Knuckles.
* Relic is a year older than Knuckles.
Shadow
* Despite 50 years, Shadow is physically the same age as Sonic
* Sticks is the same age as Amy.
* Lanolin is 4 years older than Tangle.
* Neera is 5 years older than Lilac.
* Nicole is 2 years younger than Sally.
* Out of the Hedgehog triplets, Sonia is the middle.
Silver
* Silver is a year younger than Sonic.
* Gold is a year younger than Silver.
* Galaxina is 2 years older than Silver.
Other
* Out of the Hedgehog triplets, Manic is the youngest.
* Mina is the same age as Manic.
* Kit is the same age as Tails.
* Sonar is a year older than Zooey.
* Trip is a year younger than Amy.
* Fang is 5 years older than Trip.
* Between Nicolette and Fang, Nicolette is the older twin.
* Gadget and Gizmo shared the same birthday. Gadget is the older one.
* Perci and Staci, Perci is the older twins.
* Perci is 3 years older than Zooey.
* Gadget is a year older than Perci.
* Espio and Liza are same age as Knuckles.
* Espio is 4 years younger than Bride of Conquering Storm.
* Charmy and Saffron are the same age as Cream.
* Jet is the same age as Silver.
* Jet and Tiara are the same age.
* Wave is the same age as Rouge.
* Wave is a year older than Bean.
* Storm is a year older than Wave.
* Storm is 2 years younger than Sasha.
* Mighty is a year younger than Honey.
* Mighty is the same age as Sonic.
* Ray is 2 years younger than Mighty.
* Ray is a year older than Matilda.
