  Recent advancements in our understanding of ordered magnets call for a
quantification of their entanglement content on an equal footing with classical
thermodynamic quantities, such as the total magnetic moment. We evaluate the
entanglement entropy (EE) between the two sublattices of a bipartite ordered
antiferromagnet finding it to scale with volume. Thus, the EE density becomes
an intensive property and is evaluated to be a universal
dimensionality-dependent constant when exchange is the dominant interaction.
Our analytic results are validated against the DMRG-based analysis of a
one-dimensional (1D) system, finding good agreement. Further, our evaluated EE
per bond provides a useful shortcut towards obtaining the central-cut EE in 1D,
and the area law in higher-dimensional magnets.
