Skip to content

IP Range Calculator

Read the inclusive range of a block, from the network address through the broadcast, and the tighter usable host range inside it. Firewall objects and IPAM exports usually want the inclusive pair. DHCP scopes usually want the usable pair.

CIDR prefix

CIDR prefix

65,534 usable hosts

00001010000000010000001000000011
/16
/8/16/24/32
Network bitsHost bits

Drag the line, or use the arrow keys. The result updates as it moves.

10.1.0.0/16

Private network (RFC 1918). The whole block shares this label.

Inclusive block

10.1.0.0 to 10.1.255.255

Usable host range

10.1.0.1 to 10.1.255.254

Network address

10.1.0.0

Broadcast address

10.1.255.255

Subnet mask

255.255.0.0

Total addresses

65,536

Usable hosts

65,534

First host

10.1.0.1

Last host

10.1.255.254

Wildcard mask

0.0.255.255

Historical class

A

On a conventional LAN the network and broadcast addresses are not hosts. Usable hosts are the addresses between them.

Historical class A describes the old classful split. Size the network with the CIDR prefix.

Binary

IP address
00001010.00000001.00000010.00000011
Subnet mask
11111111.11111111.00000000.00000000
Network address
00001010.00000001.00000000.00000000

Network and host bits

16 network bits16 host bits

network = address AND 255.255.0.0 = 10.1.0.0

broadcast = network OR 0.0.255.255 = 10.1.255.255

total = 2^16 = 65,536

usable = total - 2 = 65,534

Continue with this block in the range calculator, the wildcard mask, or the membership check.

Two ranges, on purpose

The inclusive block for 172.16.5.4/22 is 172.16.4.0 through 172.16.7.255. That is every address the prefix covers, including the network and broadcast.

The usable host range drops those two ends: 172.16.4.1 through 172.16.7.254. On a /31 those ends are not dropped, because both addresses are hosts.

Questions

No. The range starts at the network address of the prefix, which may be lower than the address you entered.

Use the network address with the wildcard mask, not a from-to host list, unless the ACL syntax asks for an inclusive range.

Sources

Reviewed 8 October 2026. The methodology page records what these labels do not cover.

Related tools