IP subnet / CIDR calculator
Type an IPv4 address with a /CIDR prefix (or a dotted mask) and get the network address, broadcast, usable host range, host count and wildcard mask — instantly. Basic IPv6 prefix info too. Pure bit math, right in your browser. Nothing is sent anywhere.
IPv4 address
Prefix length/24
Subnet mask
Subnet details
IPv6 address / prefix
IPv6 prefix
All calculations run on your device with plain bit math. Nothing is sent anywhere.
How it works
STEP 1
Enter an address
Type an IPv4 address — for example 192.168.1.10 — or paste full CIDR like 192.168.1.10/24.
STEP 2
Pick a prefix or mask
Choose a /CIDR from 0 to 32, or switch to a dotted subnet mask such as 255.255.255.0. The two stay in sync.
STEP 3
Read your subnet
See the network, broadcast, usable host range, host count and wildcard mask at once — then copy any value with one click.