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Kordu Tools
Network & IP Runs in browser Updated 30 Mar 2026

Subnet Calculator

Calculate network address, broadcast, host range, subnet mask, and wildcard from CIDR notation instantly.

/24

Address details

CIDR Notation192.168.1.0/24
Network Address192.168.1.0
Broadcast Address192.168.1.255
First Usable Host192.168.1.1
Last Usable Host192.168.1.254
IP ClassC

Host details

Total Hosts256
Usable Hosts254

Mask details

Subnet Mask255.255.255.0
Wildcard Mask0.0.0.255

Binary subnet mask

11111111 11111111 11111111 00000000
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How to use Subnet Calculator

  1. Enter an IP address

    Type any valid IPv4 address in dotted-decimal notation — for example, 192.168.1.0.

  2. Select a CIDR prefix

    Choose a prefix length from /0 to /32 using the dropdown, or click a common preset like /24 or /16.

  3. Review all subnet details

    See network address, broadcast address, usable host range, subnet mask, wildcard mask, total hosts, usable hosts, and IP class — all calculated instantly.

  4. Adjust as needed

    Change the IP address or prefix at any time — results update automatically as you type.

Subnet Calculator FAQ

What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation combines an IP address with a prefix length — for example, 192.168.1.0/24. The prefix length indicates how many bits identify the network, with the remaining bits identifying host addresses.

What is a wildcard mask?
A wildcard mask is the bitwise inverse of the subnet mask. It is commonly used in access control lists (ACLs) on Cisco and other network equipment to match ranges of IP addresses.

What is the difference between total hosts and usable hosts?
Total hosts is 2 raised to the power of host bits. Usable hosts subtracts two — one for the network address and one for the broadcast address. Exceptions: /31 subnets have 2 usable hosts for point-to-point links; /32 is a single host.

Does this tool support IPv6?
This version calculates IPv4 subnets only. IPv6 support may be added in a future update.

How many hosts can a /24 subnet hold?
A /24 subnet has 256 total addresses (2^8 host bits) and 254 usable host addresses after subtracting the network and broadcast addresses.

What is a /30 subnet used for?
A /30 subnet provides 4 addresses — network, 2 usable hosts, and broadcast — making it ideal for point-to-point router links where only two hosts communicate.

What does the IP class mean?
IP classes (A, B, C, D, E) are the original routing system before CIDR. Class A covers 0.0.0.0–127.255.255.255, Class B covers 128.0.0.0–191.255.255.255, and Class C covers 192.0.0.0–223.255.255.255. Classes D and E are reserved.

How do I find the network address from an IP and subnet mask?
Perform a bitwise AND of the IP address and the subnet mask. This tool does that automatically — just enter your IP and CIDR prefix.

Background

Enter any IPv4 address and CIDR prefix length to instantly calculate every subnet detail: network address, broadcast address, first and last usable host addresses, total and usable host counts, subnet mask (dotted-decimal), wildcard mask, IP class (A/B/C/D/E), and binary mask representation. Common prefix presets — /8, /16, /24, /28, /30 — let you switch between standard sizes with one click.

All maths run as pure client-side computation — no data leaves your browser.

Who is this for: network engineers designing subnets, students studying for CCNA and CompTIA Network+ exams, IT administrators planning IP address allocation, developers building network tools, and anyone who needs to quickly verify CIDR-based addressing. Covers the same calculations as Subnet Calculator by subnetonline.com and solarwinds.com — without ads.

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Learn more

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CIDR Notation and Subnetting Made Simple

Learn CIDR notation and subnetting with visual binary breakdowns. Includes a full /8 to /32 cheat sheet covering all 25 prefix lengths and real examples.