Animating on 2s and other number

What does animating on ones, twos, and threes mean?

Something you may hear a lot if you watch behind the scenes documentaries on animation, or are studying animation is the terms "on 2s" or "on 1s" What does this all mean?

24 frames per second (FPS) is the standard frame rate for movies, TV shows, and streaming video. It has been the industry standard for over a century and is considered the minimum speed needed to capture video while still maintaining realistic motion. 

Animating on 1s

Animating on 1s means that for each second of animation, there are 24 new drawings or “frames”. This is used most often in action sequences or any fast motion that needs to also be detailed. Animating on 1s has become more common in animation as studios have moved to computer animation. However animating 24 frames for every second of animation does take time and also more money

Animating on 2s

Animating on 2s means that for each second of animation, there are 12 new drawings or “frames”. This became the standard for television animation on shows like Scooby-Doo, The Flintstones, etc. This timing of animation is best for doing simple everyday motions. This should be your default way of animating until you become more familiar with timing in animation. 

Animating on 3s

Animating on 3s means that for each second of animation, there are 8 new drawings of “frames”. This timing is good for slow scenes but is also often used in anime, or on shows with low budget and or time constraints

You can mix these differing timing as needed in your animation,  you don't have to stick to just one set.