It really depends on how you are boxing. Assuming a four byte object header a boxed float32 consumes 8 bytes. A boxed float64 consumes 12 bytes but! Is quite li

It really depends on how you are boxing. Assuming a four byte object header a boxed float32 consumes 8 bytes. A boxed float64 consumes 12 bytes but! Is quite likely to require 4 bytes of padding to align it to an 8 byte boundary. It adds up quickly if you have many floats.