In the tv series, she's theorized to be 15-16 nothing is supporting that theory, but it's a known fact that the Titans were aged down to fit the younger audience the tv series targeted. This fact isn't surprising if you're watching the newest live-action Teen Titans series, but in the tv series, she's not older than Robin or Cyborg. This age range makes her the oldest member of the Comic Teen Titans. Then, she reveals that her sister had her enslaved for six years, putting her age range around 20-23. She doesn't state her age, but her physique puts her around the 14-16 age range. She's talking about her past and mentions training with the Warlords of Okaara.
Unlike some of the other Titans, Comic Starfire gives a vague time frame that could help to decide her age. Starfire Between the Series and the Comic
