A small high performance utility for measuring object memory usage in Java.

long bytes = MemoryUtil.sizeOf( object );This utility is not meant to replace the excellent range of profiling tools available for Java such as VisualVM, YourKit or JProfiler, it is aimed for runtime debug/logging of selected structures in a production system.

Tutorial Calculations Common primitive and object sizes:

boolean 1 byte byte 1 byte short 2 bytes integer 4 bytes long 8 bytes float 4 bytes double 8 bytes

Boolean 16 bytes Byte 16 bytes Short 16 bytes Integer 16 bytes Long 16 bytes Float 16 bytes Double 16 bytes Currency 16 bytes Date 24 bytes

BigInteger ~56 bytes BigDecimal ~144 bytes GregorianCalendar ~460 bytes