Browser-only network math

Subnet calculator

Calculate IPv4 network details locally in your browser: subnet mask, network address, broadcast address, total addresses, usable hosts, and usable range.

IPv4 input

Calculate a subnet

Choose CIDR or subnet mask. The paired field stays in sync.

Results

Calculated network

192.168.1.1/24 resolves to 192.168.1.0/24.

Network address

192.168.1.0

Broadcast address

192.168.1.255

Subnet mask

255.255.255.0

Wildcard mask

0.0.0.255

Total addresses

256

Usable hosts

254

Usable range

192.168.1.1 - 192.168.1.254

Standard subnets reserve the network and broadcast addresses.

Bit view

Binary breakdown

Dots stay aligned by octet so the mask boundary is easier to read.

IP address

11000000.10101000.00000001.00000001

Subnet mask

11111111.11111111.11111111.00000000

Network

11000000.10101000.00000001.00000000

Broadcast

11000000.10101000.00000001.11111111

Use this when

Translate CIDR into usable addresses

Enter an IPv4 address, then choose a CIDR prefix or subnet mask to find the network address, broadcast address, wildcard mask, host count, and usable range. The math runs locally in the browser.

This is useful when planning VLANs, checking firewall rules, reading route tables, or confirming whether two addresses should be in the same subnet.