IP Calculator
Subnet, CIDR, hosts and binary breakdown
Accepts: CIDR (x.x.x.x/n), IP + mask (x.x.x.x y.y.y.y), or just IP (→ /24)
Invalid IP address or subnet mask.
Results
Binary representation
Subnet splitter
Split this network into smaller subnets:
What is a subnet mask?
A subnet mask defines which part of an IP address belongs to the network (network bits) and which part identifies hosts. In CIDR notation, /24 means 24 network bits → 256 addresses, 254 usable hosts. The first address (network) and last address (broadcast) are reserved and not assigned to hosts.
Private vs public IP addresses
The RFC 1918 private ranges are: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. These are not routed on the internet. NAT (Network Address Translation) is used to allow internal hosts to communicate with the internet.
Subnet reference table
| CIDR | Mask | 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 |
| /31 | 255.255.255.254 | 2 (p2p) |
| /32 | 255.255.255.255 | 1 |
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