Rio Calculator

IP Subnet Calculator

Enter in CIDR notation, e.g. 192.168.1.0/24 or 10.0.0.1/8

Subnet Details

IP Address192.168.1.0
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 Hosts256
Usable Hosts254
CIDR Notation192.168.1.0/24

Quick Summary

192.168.1.0

Network

192.168.1.255

Broadcast

254

Usable Hosts

24

CIDR

What is an IP Subnet Calculator?

An IP subnet calculator breaks down an IPv4 address and CIDR prefix into its network components: network address, broadcast address, subnet mask, usable host range, and the total number of usable hosts. It's an essential tool for network engineers, IT administrators, and students learning networking.

CIDR (Classless Inter-Domain Routing) notation like 192.168.1.0/24 is the modern standard for defining IP networks. The "/24" indicates that the first 24 bits are the network prefix, leaving 8 bits for host addresses.

How to Use

  1. Enter IP/CIDR: Type an IPv4 address with CIDR prefix, e.g. 192.168.1.0/24.
  2. Instant results: The calculator shows network address, broadcast, subnet mask, host range, and usable host count.
  3. Try common private ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.

Frequently Asked Questions

What is a subnet mask?

A subnet mask is a 32-bit number that divides an IP address into network and host portions. /24 corresponds to 255.255.255.0 — the first 24 bits identify the network, the last 8 bits identify hosts within it (allowing 254 usable addresses).

What are private IP ranges?

RFC 1918 defines three private ranges not routed on the public internet: 10.0.0.0/8 (Class A, 16M addresses), 172.16.0.0/12 (Class B, 1M addresses), and 192.168.0.0/16 (Class C, 65K addresses). Home routers typically use 192.168.1.x or 192.168.0.x.

Why are 2 addresses reserved per subnet?

The first address is the network address (identifies the subnet itself) and the last is the broadcast address (sends packets to all hosts). Neither can be assigned to a device, so a /24 gives 256 − 2 = 254 usable hosts.

What is CIDR and why was it introduced?

CIDR (Classless Inter-Domain Routing) replaced the old Class A/B/C system in 1993 to allow flexible subnet sizes and slow IPv4 exhaustion. It enables routing aggregation (supernetting) which keeps internet routing tables smaller.

Common CIDRs

  • /816,777,214 hosts
  • /1665,534 hosts
  • /24254 hosts
  • /25126 hosts
  • /2814 hosts
  • /302 hosts
  • /32single host

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