tools ▸ subnet calculator

Subnet anyIPv4 block.

Type an address with a CIDR prefix — like 192.168.10.0/24 — and get the network, broadcast, usable range, masks and host count instantly.

IPv4 address / CIDR

or pick a prefix

runs 100% in your browser — nothing is uploaded or stored

subnet calculator ▸ explained

What you need
to know.

Calculate network, broadcast, usable host range and mask from any IPv4 CIDR.

CIDR

/24 means the first 24 bits are the network. Each step down doubles the hosts: /23 = 510 usable, /22 = 1,022.

usable

The first address is the network and the last is broadcast, so a /29 has 8 addresses but 6 usable hosts.

wildcard

The wildcard mask is the inverse of the netmask — used in Cisco ACLs, OSPF and some firewall rules.

related ▸ more free tools

faq ▸ before you buy

How many usable IPs are in a /24?+

A /24 has 256 addresses and 254 usable hosts, because the network and broadcast addresses cannot be assigned.

What are /31 and /32 used for?+

A /32 is a single host (common for a VPS's main IP). A /31 has two addresses and is used for point-to-point links (RFC 3021).

Does this calculator support IPv6?+

This version handles IPv4. IPv6 subnetting is on our roadmap for the tools suite.

~$ provision --region in ✓ done in 47s