CIDR Subnet Calculator

Calculate network address, broadcast, hosts from CIDR notation

100% In-BrowserNo Server UploadFree, No Signup

Network

Input (CIDR Notation)

Calculation Result

How to Use

Enter CIDR notation
Enter an IPv4 address with a prefix length separated by a slash (e.g. 192.168.1.0/24).
Click Convert
Press "Convert" to calculate network address, broadcast, subnet mask, host count, etc.
Copy result
Use the "Copy" button to copy the results to your clipboard.

CIDR Subnet Calculator Examples

/24 subnet calculation

Input

192.168.1.0/24

Output

Network: 192.168.1.0/24
Network Address: 192.168.1.0
Broadcast: 192.168.1.255
Subnet Mask: 255.255.255.0
Wildcard: 0.0.0.255
Hosts: 254
First Host: 192.168.1.1
Last Host: 192.168.1.254

/8 subnet calculation

Input

10.0.0.0/8

Output

Network: 10.0.0.0/8
Network Address: 10.0.0.0
Broadcast: 10.255.255.255
Subnet Mask: 255.0.0.0
Wildcard: 0.255.255.255
Hosts: 16777214
First Host: 10.0.0.1
Last Host: 10.255.255.254

Features

Network and broadcast address calculation
Subnet mask and wildcard mask display
Usable host count with first/last host
Binary subnet mask representation
Supports /0 to /32 prefix lengths
Local processing (your input is not sent to servers)
Dark mode support

FAQ

What is CIDR notation?

CIDR (Classless Inter-Domain Routing) notation represents a network range using an IP address followed by a slash and prefix length. For example, 192.168.1.0/24 means the first 24 bits define the network portion.

How is host count calculated?

Usable hosts = 2^(32-prefix) - 2. Two addresses are subtracted for the network address and broadcast address. /31 and /32 are special cases.

Is my data sent to a server?

No. All calculations happen locally in your browser via JavaScript. No data is ever transmitted externally.