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IPv4 subnet / CIDR calculator

Calculate an IPv4 / CIDR subnet: mask, range, broadcast and host count.

Réseau / Network192.168.1.0
Masque / Mask255.255.255.0
CIDR/24
Wildcard0.0.0.255
Broadcast192.168.1.255
Premier hôte / First host192.168.1.1
Dernier hôte / Last host192.168.1.254
Hôtes utilisables / Usable hosts254
Total adresses256

🔒 100% client-side — no data sent

Enter an IPv4 address and a CIDR prefix to get the mask, network address, host range, broadcast and number of available hosts. A fast tool for planning or checking a network split. Calculations run locally in your browser, with no data sent anywhere.

What is it for?

  • Find the usable host range of a network
  • Convert a CIDR prefix to a subnet mask
  • Check the broadcast address before a config
  • Estimate the number of hosts in a subnet

FAQ

What is the difference between /24 and 255.255.255.0?

None: /24 is the CIDR notation for the mask 255.255.255.0. Both describe the same network split.

Does the host count include the network and broadcast?

The usable host count excludes the network and broadcast addresses.

Is IPv6 supported?

This tool is dedicated to IPv4 and IPv4 CIDR.