It depends upon the soil mix, and the volume of soil mix, as well as the cultural conditions -
namely, light/heat exposure.

More importantly, this tree belongs outside. It won't live long in an interior setting.

I would put this tree in a much larger container, in order to thicken and develop the trunk.

Josh

Dangerz,, Japanese maple are outdoor trees,they will not live inside your home. that said you need to pot your tree in something bigger to alowe root and tree groweth with good draining soil water when the soil is dry 2 inches or so,do not let the roots stand in water.your tree looks good more growing room is what it needs try not to disturb the roots when transplanting it is the wrong time of the year..good luck get it outside john