Enter an IPv4 address and prefix length. Results are calculated locally.

Common home subnet

A /24 network contains 256 total addresses, usually with 254 traditional host addresses after the network and broadcast addresses.

Reviewed for clarity and general compatibility. Router menus vary by model and firmware.

What the subnet result tells you

The network address identifies the subnet, the mask or prefix defines its size, and the broadcast address marks the top of a conventional IPv4 subnet. The usable-host count is a planning figure; routers may reserve addresses or apply different rules on point-to-point prefixes.

Common uses

  • Confirm whether two local addresses belong to the same subnet.
  • Plan DHCP pools without overlapping static reservations.
  • Document VLAN or guest-network ranges.
  • Understand why a device sends traffic to the default gateway.

The calculator does not test reachability, firewall rules, VLAN tagging or whether the proposed range conflicts with an upstream network.

Final verification step

When planning DHCP, leave deliberate space for infrastructure addresses and reservations. Document the router, access points, switches, printers and servers so a future administrator can understand why parts of the range were excluded.