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CIDR / Subnet Calculator

Calculate network address, broadcast, netmask, wildcard mask and usable host range for any IPv4 CIDR block.

🔒 Runs locally — your input never leaves this browser tab

IPv4 address with prefix

Network
Broadcast
Netmask
Wildcard (ACL)
First usable host
Last usable host
Total addresses
Usable hosts
Binary mask
Address type

CIDR prefix table

Prefix	Netmask	Addresses
/8	`255.0.0.0`	16,777,216
/12	`255.240.0.0`	1,048,576
/16	`255.255.0.0`	65,536
/20	`255.255.240.0`	4,096
/22	`255.255.252.0`	1,024
/23	`255.255.254.0`	512
/24	`255.255.255.0`	256
/25	`255.255.255.128`	128
/26	`255.255.255.192`	64
/27	`255.255.255.224`	32
/28	`255.255.255.240`	16
/29	`255.255.255.248`	8
/30	`255.255.255.252`	4
/31	`255.255.255.254`	2
/32	`255.255.255.255`	1

Private ranges (RFC 1918)

10.0.0.0/8 — 16.7 million addresses
172.16.0.0/12 — 1 million addresses
192.168.0.0/16 — 65,536 addresses
100.64.0.0/10 — carrier-grade NAT (RFC 6598), also used by Tailscale