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Subnet Calculator

Enter an IPv4 address and CIDR to get network, broadcast, host range and mask details.

IP address192.168.1.10
Network address192.168.1.0
Broadcast address192.168.1.255
Subnet mask255.255.255.0
Wildcard mask0.0.0.255
First usable host192.168.1.1
Last usable host192.168.1.254
Total addresses256
Usable hosts254
IP classC
Private addressYes
IP in binary11000000.10101000.00000001.00001010
Mask in binary11111111.11111111.11111111.00000000

Frequently Asked Questions

What is a CIDR prefix?

CIDR notation like /24 says how many of the 32 IPv4 bits belong to the network. A /24 leaves 8 bits for hosts, giving 256 addresses of which 254 are usable.

Why are two addresses unusable?

The first address identifies the network itself and the last is the broadcast address, so usable hosts run from network+1 to broadcast-1. Point-to-point /31 links are a special exception in practice.

What is the wildcard mask?

The wildcard mask is the inverse of the subnet mask (0s become 1s and vice versa). It is used in router ACLs and OSPF configuration, notably on Cisco equipment.

Does it support IPv6?

This calculator is IPv4-only. IPv6 subnets are usually /64 and the address counts are astronomically large, so they rarely need this style of calculation.

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