What is the difference between network and broadcast addresses?

The network address identifies the subnet itself (host bits all zero) and the broadcast address targets every host in it (host bits all one). Neither is assignable to a device in standard subnets.

How is the wildcard mask related to the subnet mask?

The wildcard is the bitwise inverse of the subnet mask — where the mask has 0s, the wildcard has 1s. ACLs and OSPF network statements use it to match address ranges.

How many usable hosts does my prefix give me?

Raise 2 to the power of host bits (32 minus prefix) and subtract 2 for network and broadcast. A /24 has 8 host bits, so 2^8 − 2 = 254 usable hosts.

Why is 192.168.1.10 a private address?

The ranges 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 are reserved for private networks and never routed on the public internet, which is why home routers use them.

Free Online Tool

Subnet Calculator – IPv4 Subnet & IP Range

Free IPv4 subnet calculator — enter an IP with a CIDR prefix or mask to get the network, broadcast, usable hosts, wildcard and binary octets.

Reviewed by Prime Metric • Updated September 2026 WhatsApp

IP Address

CIDR Prefix (0–32)

Subnet Mask

Network Addresses

CIDR notation192.168.1.0/24

Network address192.168.1.0

Broadcast address192.168.1.255

Subnet mask255.255.255.0

Wildcard mask0.0.0.255

Host Range

First usable host192.168.1.1

Last usable host192.168.1.254

Usable hosts254

Total addresses256

IP classClass C

Address typePrivate

Binary Octets

IP11000000.10101000.00000001.00001010

Mask11111111.11111111.11111111.00000000

Network11000000.10101000.00000001.00000000

About this Tool

The IPv4 Subnet Calculator splits any IPv4 address and CIDR prefix (or subnet mask) into its network address, broadcast address, usable host range, wildcard mask and binary octets. It handles edge cases like /31 point-to-point links and /32 single-host routes, and flags the address class and private-versus-public type. Results update from the pre-filled 192.168.1.10/24 demo so you can explore instantly.

Common Use Cases

Plan Office Networks

Size VLANs and DHCP scopes by checking usable host counts before assigning a prefix.

Write Firewall Rules

Derive exact network and wildcard addresses for ACLs and security-group CIDR blocks.

Study for Certifications

Practice subnetting with binary octets visible for CCNA and Network+ exam prep.

Debug Connectivity

Confirm two hosts share a network address when pings fail across subnets.

Pro Tips

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Prefix and Mask Stay in Sync
Typing a valid prefix auto-fills its mask and vice versa — a quick way to memorize pairs like /24 with 255.255.255.0.
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Remember /31 and /32
These have no traditional broadcast range: /31 gives two usable point-to-point addresses and /32 is a single host route.
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Usable Means Minus Two
For prefixes /30 and shorter, subtract the network and broadcast addresses from the total to get assignable hosts.

FAQs

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