Age only matters in two instances on Tumblr:
- You must be at least 13 years old to use Tumblr. As stated in our Terms of Service, “We're serious: it's a hard rule, based on U.S. federal and state legislation. ‘But I’m, like, 12.9 years old!’ you plead. Nope, sorry. If you're younger than 13, don't use Tumblr. Ask your parents for a Playstation 4, or try books.”
- You must be at least 18 years old to turn Safe Mode off. If you’re under the age of 18, Safe Mode is enabled for you and you can’t disable it.
Your age is calculated according to the age you gave during signup, and it’s not possible to edit that age.
Since Tumblr just asks for your age, our system only knows your birth year rather than your specific birthday. It rounds down to the next whole year to estimate your age. To be considered “over 18” by our system in 2017, you would have needed to sign up with an age indicating that your birth year was 1999 or earlier.