What age is bart simpsons?

He is 10 years old. His bithday is April 1.

Bart Simpson's age is permanent because after the years he would start getting older and more mature so he wouldn't be able to get into the fun, crazy situations that we love to see him get into....

Bart is 10 years old as permanent, Lisa is 8 but might not be the permanent age.

Lisa Simpson has been 8 years old for the past 20 years.

Around 1 or 2