What is Subnet Calculator?

Calculates network, broadcast, netmask and host counts for an IPv4 subnet.

How do I use Subnet Calculator?

Type or paste your data into the field on this page and press the button. The result is calculated instantly in your browser — nothing is uploaded.

Is Subnet Calculator free?

Yes, Subnet Calculator is completely free. No signup, no downloads and no usage limits.

Subnet Calculator

Developer

Calculate the network address, broadcast, netmask and usable host count for any IPv4 subnet /0 to /32. Free and fully client-side; addresses never leave your browser.

IP address

Prefix

What is a Subnet Calculator?

A Subnet Calculator takes an IPv4 address and a prefix length and computes the network address, broadcast address, netmask, total number of hosts and usable hosts for that subnet. It is used when planning IP ranges, VLANs, subnets in cloud services and container networks.

A worked example

For 192.168.1.0/24 the network address is 192.168.1.0, the broadcast is 192.168.1.255, the netmask is 255.255.255.0, the total number of hosts is 256 and the usable hosts are 254.

Why are usable hosts fewer than total hosts?

The network address and the broadcast address are always reserved and cannot be assigned to a device. A /24 subnet therefore holds 256 addresses but offers 254 usable hosts.

Frequently Asked Questions

What is Subnet Calculator?
Calculates network, broadcast, netmask and host counts for an IPv4 subnet.
How do I use Subnet Calculator?
Type or paste your data into the field on this page and press the button. The result is calculated instantly in your browser — nothing is uploaded.
Is Subnet Calculator free?
Yes, Subnet Calculator is completely free. No signup, no downloads and no usage limits.