Subnet Calculator

Calculate IPv4 subnet details from an IP address and CIDR prefix. Get network/broadcast addresses, host range, wildcard mask, binary breakdown, and split subnets visually.

Subnet Calculator

Calculate network details from an IP address and subnet mask or CIDR notation.

IP Address
192.168.1.0
11000000.10101000.00000001.00000000
Subnet Mask
255.255.255.0
11111111.11111111.11111111.00000000
CIDR Notation
/24
Wildcard Mask
0.0.0.255
00000000.00000000.00000000.11111111
Network Address
192.168.1.0
11000000.10101000.00000001.00000000
Broadcast Address
192.168.1.255
11000000.10101000.00000001.11111111
First Usable Host
192.168.1.1
Last Usable Host
192.168.1.254
Total Addresses
256
Usable Hosts
254
IP Class
Class C
IP Type
Private (RFC 1918)
IPv4-mapped IPv6
::ffff:c0a8:100
Hex Notation
c0.a8.01.00
FieldOctet 1Octet 2Octet 3Octet 4Decimal
IP Address11000000101010000000000100000000192.168.1.0
Subnet Mask11111111111111111111111100000000255.255.255.0
Network11000000101010000000000100000000192.168.1.0
Broadcast11000000101010000000000111111111192.168.1.255
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Network bits (24)Host bits (8)
Subnet Splitter

Split 192.168.1.0/24 into smaller subnets:

#NetworkRangeBroadcastHosts
1192.168.1.0/25192.168.1.1 - 192.168.1.126192.168.1.127126
2192.168.1.128/25192.168.1.129 - 192.168.1.254192.168.1.255126
Common Private Ranges
All calculations run locally in your browser. No data is sent anywhere. Supports IPv4 only.

What is a Subnet Calculator?

A subnet calculator takes an IPv4 address and a subnet mask (or CIDR prefix length) and computes the full network details: network address, broadcast address, usable host range, wildcard mask, and more. It is essential for network engineers, sysadmins, and anyone studying for Cisco CCNA, CompTIA Network+, or similar certifications.

Key Features

  • Full Subnet Details: Network address, broadcast, first/last host, total addresses, usable hosts, IP class, and type (private/public/loopback).
  • Binary Breakdown: See every address in binary, octet by octet, with a visual mask showing network vs host bits.
  • Subnet Splitter: Divide a network into smaller subnets by choosing a longer prefix. See all resulting subnets with their ranges.
  • CIDR Support: Enter addresses in CIDR notation (e.g. 192.168.1.0/24) or select the prefix from a dropdown.
  • Common Presets: One-click presets for RFC 1918 private ranges, loopback, and link-local networks.
  • IPv6 Mapped: Shows the IPv4-mapped IPv6 address and hex notation.

How to use the Subnet Calculator

  1. Enter an IPv4 address (e.g. 192.168.1.0) or paste a CIDR block (e.g. 10.0.0.0/16).
  2. Select the subnet prefix length from the dropdown or quick-select buttons.
  3. Click Calculate to see all network details, binary breakdown, and mask visualization.
  4. Use the Subnet Splitter to divide the network into smaller subnets.

Understanding CIDR Notation

CIDR (Classless Inter-Domain Routing) notation appends a prefix length to an IP address, like 192.168.1.0/24. The prefix length indicates how many leading bits of the address identify the network. A /24 means 24 network bits and 8 host bits, giving 256 total addresses (254 usable hosts).

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