Enter an address with its mask: the calculator gives you the network, broadcast, first and last usable address, number of hosts, and ready-to-copy RouterOS commands for the address, pool, and DHCP network. The calculation happens in your browser. For IPv6, see the IPv6 IP calculator.

Enter the address with the mask in bits (/24) or decimal (255.255.255.0).

1. Assign the address to the interface

Ready-to-copy RouterOS commands are for those in the dojo. Entry is free: with your email you get them in one click, along with real-time security alerts.

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2. DHCP server on that network

Ready-to-copy RouterOS commands are for those in the dojo. Entry is free: with your email you get them in one click, along with real-time security alerts.

Enter the dojo for free I am already registered

The pool excludes the router's address. One-hour lease: adjust it to the type of installation.

How to read the result?

  • Network: the first address of the subnet; it identifies the network and is not assigned to a device;
  • Broadcast: the last address, used to communicate with all devices on the subnet;
  • First and last usable IP: the range assignable to routers and clients. Usually, the router takes the first one, and the DHCP pool takes the rest;
  • Wildcard: the “inverted” mask, useful in some ACLs and in other vendors’ documentation;
  • /31 and /32: special cases. A /31 is used for point-to-point links and has two addresses, both usable; a /32 identifies a single address.

How large should a subnet be?

It depends on the installation: count the devices that will be present at the same time, multiply by the number of devices per person, and leave margin for occupied DHCP leases. A practical example is in the howto How to create a WiFi hotspot with MikroTik.