IP subnet calculator
Enter an address with its prefix, like 192.168.1.130/26 or 2001:db8::1/48, to see the whole subnet.
CIDR (10.0.0.5/8), address and mask (10.0.0.5 255.0.0.0), or an IPv6 prefix.
Split into smaller subnets
| Subnet | Address range |
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Questions people ask
What does /24 mean?
It is the number of leading bits that identify the network. An IPv4 address has 32 bits, so /24 leaves 8 bits for hosts: 256 addresses, of which 254 can be given to devices once the network and broadcast addresses are set aside.
Why does a /31 have 2 usable hosts?
On point-to-point links RFC 3021 lets both addresses of a /31 be used, since there is no need for a network or broadcast address. A /32 is a single host.
How big is an IPv6 /64?
2⁶⁴, about 18.4 quintillion addresses. /64 is the standard size for one IPv6 network; sites usually get a /48 or /56 to split into many /64s.