🌐 IP Subnet Calculator

Enter an IPv4 address and prefix to see its network, broadcast, host range and masks – and divide it into smaller subnets.

Quick answer: 192.168.1.10/24 belongs to network 192.168.1.0 with subnet mask 255.255.255.0, broadcast address 192.168.1.255 and 254 usable hosts (192.168.1.1 – 192.168.1.254).

Updated October 2026 · Free · No sign-up · Works on any device

Network

192.168.1.0/24

254 usable hosts · Private (RFC 1918)

IP address	192.168.1.10
Network address	192.168.1.0
Broadcast address	192.168.1.255
First usable host	192.168.1.1
Last usable host	192.168.1.254
Subnet mask	255.255.255.0
Wildcard mask	0.0.0.255
CIDR notation	/24

Total addresses: 256
Usable hosts: 254
IP class: C
Reverse DNS zone: 1.168.192.in-addr.arpa

Binary view

	Dotted decimal	Binary
IP address	192.168.1.10	11000000.10101000.00000001.00001010
Subnet mask	255.255.255.0	11111111.11111111.11111111.00000000
Wildcard	0.0.0.255	00000000.00000000.00000000.11111111
Network	192.168.1.0	11000000.10101000.00000001.00000000
Broadcast	192.168.1.255	11000000.10101000.00000001.11111111

The first 24 bits are the network part; the remaining 8 bits number the hosts.

4 subnets of /26

#	Network	Usable range	Broadcast	Hosts
1	192.168.1.0/26	192.168.1.1 – 192.168.1.62	192.168.1.63	62
2	192.168.1.64/26	192.168.1.65 – 192.168.1.126	192.168.1.127	62
3	192.168.1.128/26	192.168.1.129 – 192.168.1.190	192.168.1.191	62
4	192.168.1.192/26	192.168.1.193 – 192.168.1.254	192.168.1.255	62

Common prefix lengths

CIDR	Subnet mask	Addresses	Usable hosts
/8	255.0.0.0	16,777,216	16,777,214
/16	255.255.0.0	65,536	65,534
/20	255.255.240.0	4,096	4,094
/22	255.255.252.0	1,024	1,022
/23	255.255.254.0	512	510
/24	255.255.255.0	256	254
/25	255.255.255.128	128	126
/26	255.255.255.192	64	62
/27	255.255.255.224	32	30
/28	255.255.255.240	16	14
/29	255.255.255.248	8	6
/30	255.255.255.252	4	2
/31	255.255.255.254	2	2
/32	255.255.255.255	1	1

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Preview

How to use the subnet calculator

Type an IPv4 address and its prefix length (or CIDR notation such as 10.0.0.0/16). Optionally enter how many subnets you need, and the calculator divides the network into equal-sized blocks.

The maths

Network = IP AND mask · Broadcast = network OR wildcard · Wildcard = NOT mask

Addresses = 2^(32 − prefix) · Usable hosts = addresses − 2

Worked example

For 192.168.1.10/24 the mask is 24 one-bits: 255.255.255.0. ANDing gives the network 192.168.1.0; setting the 8 host bits to 1 gives the broadcast 192.168.1.255. Hosts run from 192.168.1.1 to 192.168.1.254 – 254 usable addresses. Split into 4 subnets, it becomes 192.168.1.0/26, .64/26, .128/26 and .192/26, each with 62 hosts.

Subnet cheat sheet

CIDR	Mask	Usable hosts
/8	255.0.0.0	16,777,214
/16	255.255.0.0	65,534
/24	255.255.255.0	254
/25	255.255.255.128	126
/26	255.255.255.192	62
/27	255.255.255.224	30
/28	255.255.255.240	14
/29	255.255.255.248	6
/30	255.255.255.252	2

IPv6 in brief

IPv6 addresses are 128 bits. Home and office LANs almost always use a /64 (2⁶⁴ addresses), ISPs typically delegate a /48 or /56 to each customer, and there is no broadcast address. A /48 contains 65,536 /64 subnets.

Frequently asked questions

How many hosts are in a /24 subnet?

A /24 has 256 addresses. The first is the network address and the last is the broadcast address, leaving 254 usable host addresses.

How do I calculate the number of usable hosts?

Usable hosts = 2^(32 − prefix) − 2. For a /26 that is 2⁶ − 2 = 62. Point-to-point /31 links use both addresses (RFC 3021), and a /32 is a single host.

What is a wildcard mask?

The wildcard mask is the inverse of the subnet mask – 0 bits must match, 1 bits can be anything. It is used in Cisco ACLs and OSPF; for 255.255.255.0 the wildcard is 0.0.0.255.

What are the private IP address ranges?

RFC 1918 reserves 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 for private networks. They are not routed on the public internet and are normally used behind NAT.

How do I split a network into subnets?

Borrow host bits: each extra prefix bit doubles the number of subnets and halves their size. Splitting a /24 into 4 subnets uses 2 bits, giving four /26 networks of 62 usable hosts each.

🌐 IP Subnet Calculator