- Recommended prefix
- /26
- Subnet mask
- 255.255.255.192
- Block size
- 64 total addresses
- Usable hosts
- 62 usable hosts
The host planner avoids /31 and /32 recommendations because most LAN planning still reserves network and broadcast addresses.
Free networking calculator
Subnet Calculator
Calculate IPv4 CIDR ranges, subnet masks, wildcard masks, network and broadcast addresses, usable hosts, and the smallest subnet size for a host count.
- IPv4 CIDR
- Subnet mask
- Wildcard mask
- Usable hosts
Subnet result
CIDR breakdown
Calculated block192.168.1.25/24
- 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
- Total addresses
- 256
- Usable hosts
- 254
- Network CIDR
- 192.168.1.0/24
- Binary mask
- 11111111.11111111.11111111.00000000
- Usable range
- 192.168.1.1 - 192.168.1.254
- Address type
- Private RFC1918 address range
Subnet sizing
Find a subnet size from host count
Enter the number of usable devices you need and the planner recommends the smallest traditional IPv4 subnet block that can hold them.
How subnet calculation works
IPv4 addresses are 32-bit numbers usually written as four decimal octets. CIDR notation, such as 192.168.1.25/24, says how many of those bits belong to the network portion. The remaining bits are available for host addresses inside that block.
The subnet mask is the dotted-decimal version of the network bits. A /24 prefix becomes 255.255.255.0 because the first 24 bits are set to 1 and the last 8 bits are host bits.
Network address, broadcast address, and usable hosts
The network address is the first address in the block. The broadcast address is the last address in most IPv4 subnets. Traditional LAN subnets reserve both, so a /24 has 256 total addresses and 254 usual host addresses.
A /31 is a special case commonly used for point-to-point links, and a /32 identifies a single host route. This calculator shows those ranges as valid, but the host planner recommends traditional blocks for ordinary device networks.
Wildcard masks
A wildcard mask is the inverse of the subnet mask. Network teams often see wildcard masks in access control lists and routing configurations. For example, 255.255.255.0 has a wildcard mask of 0.0.0.255.
If the subnet mask bits say which bits must match, the wildcard bits say which bits can vary. That makes wildcard masks useful when a rule needs to match a whole subnet instead of one host.
Common subnetting mistakes
Common mistakes include forgetting to subtract network and broadcast addresses, confusing /24 with 24 usable hosts, or typing an address from inside a subnet and assuming it is the network address. The network address is calculated from the address and prefix together.
When planning a real network, leave room for gateways, printers, virtual machines, DHCP reservations, monitoring systems, and future growth. A subnet that fits exactly on paper can become frustrating once devices are added.