How can I determine the block size of the filesystem on my Android? I'm creating a bunch of flash cards for use with AnkiDroid and many of them contain images or sound files.

I would like to find a balance between image/audio file size, and clarity, without wasting a ton of space with files that exceed a block boundary by just a few bytes.

So I'd like to know how to determine the filesystem block size on any given android device. Is there an easy way to do this?
You can use tune2fs (shell command) for this. The target output entry is 'Block size'. The corresponding block device (mmcblk1p1) depends on your hardware and needs to be replaced respectively. 

tune2fs -l /dev/block/mmcblk1p1