Subnet Calculator

Give it an IPv4 address with a prefix and it works out the network, the broadcast, the usable host range and everything else you would otherwise count on your fingers.

Address

IP address and prefix

Accepts 10.0.0.1/8, 10.0.0.1 255.0.0.0, or a bare address, which is treated as /24.

Or pick a prefix

The block

Waiting: —

Tap a row to copy it.

Where the split falls

Blue is the network part, grey is the host part.

Is an address inside it

Address to test

Split it up

Into /