IP Subnet Calculator (CIDR)

Enter an IPv4 or IPv6 address with a prefix to get the network, netmask, host range, broadcast and number of addresses.

Network: 192.168.1.0/24
Netmask: 255.255.255.0
Wildcard mask: 0.0.0.255
Broadcast: 192.168.1.255
First address: 192.168.1.1
Last address: 192.168.1.254
Usable hosts: 254
Total addresses: 256
Address type: Private (RFC 1918)

Binary

11000000.10101000.00000001.00000000

■ network bits ■ host bits

How it works

CIDR in short

Prefix length

The number after the slash is how many leading bits identify the network. /24 leaves 8 bits, or 256 addresses, for hosts.

Usable hosts

In IPv4 the first address names the network and the last is the broadcast, so a /24 has 254 usable hosts. /31 and /32 are special cases used for point-to-point links and single hosts.

IPv6

IPv6 networks are normally /64. A site usually receives a /48 or /56 and splits it into /64 subnets.

FAQ

Frequently asked questions

What netmask is /24?

255.255.255.0. A /16 is 255.255.0.0 and a /28 is 255.255.255.240.

Is my data sent anywhere?

No. The calculator runs entirely in your browser.

More free tools

All tools

What Is My IPYour public IP address, reverse DNS and browser details.Ping and TraceroutePing, traceroute and MTR from probes worldwide.Port CheckerCheck whether a TCP port is open from the internet.IP LookupLocation, network (ASN) and reverse DNS of any IP address.SSL CheckerCheck a site's certificate, chain, expiry and TLS versions.DNS LookupQuery A, AAAA, MX, TXT, NS, CAA and more from public resolvers.WHOIS LookupRegistrar, dates, status and nameservers of any domain.HTTP Headers CheckerSee status codes, redirects and response headers of a URL.

Cloud servers with full root access

KVM servers with full root access

Cloud Servers