SubnetCalc Online

What is this Subnet Calculator?

When working with networks it is often required to quickly calculate the network boundaries of a subnet from a CIDR address or subnet with network mask. CIDR notation format is a way to express IP addresses and their associated routing prefix. It appends a slash character to the address and the decimal number of leading bits of the routing prefix, e.g., 192.168.2.0/24 for IPv4, and 2001:db8::/32 for IPv6.

Format of the Subnet to Lookup

Enter the CIDR network address to lookup using one of the following formats.

192.168.1.0/24
10.10.0.0/16

IPv6 Subnet Lookup

Calculate IPv6 CIDR network addresses using the same format. Simply enter the IPv6 address and include a CIDR notation.

Here are some examples:

API for the Subnet Calculator

In addition to the web form on this page, you are able to calculate a network subnet using the API endpoint.

Subnet Calculator API - Simple Text Response

curl -s https://api.hackertarget.com/subnetcalc/?q=192.168.1.0/24
Address       = 192.168.1.0
Network       = 192.168.1.0/24
Netmask       = 255.255.255.0
Broadcast     = 192.168.1.255
Wildcard Mask = 0.0.0.255
Hosts Bits    = 8
Max. Hosts    = 256
Host Range    = 192.168.1.1 - 192.168.1.254
IP Class      = C
CIDR Notation = 192.168.1.0/24
IP Version    = IPv4
Is Private    = Yes
DNS Hostname  = No hostname found

Subnet Calculator API - JSON response

curl -s "https://api.hackertarget.com/subnetcalc/?q=192.168.1.0/24&output=json" | jq
{
  "query": "192.168.1.0/24",
  "address": "192.168.1.0",
  "network": "192.168.1.0/24",
  "netmask": "255.255.255.0",
  "broadcast": "192.168.1.255",
  "wildcard_mask": "0.0.0.255",
  "hosts_bits": 8,
  "max_hosts": 256,
  "host_range": "192.168.1.1 - 192.168.1.254",
  "is_private": true,
  "ip_class": "C",
  "cidr_notation": "192.168.1.0/24",
  "ip_version": "IPv4",
  "dns_hostname": "No hostname found"
}

The API is simple to use and aims to be a quick reference tool. Like all our IP Tools there is a limit of 50 queries per day or you can Remove limits with a Full Membership.