Enter an IPv4 address with a CIDR prefix to calculate its complete subnet details.
NETWORK DETAILS
CALCULATION RESULT
HOW TO USE IT
Use the address and prefix from your network plan, server, router, or hosting control panel.
Type all four decimal octets, such as 192.168.1.10.
Append a slash and a prefix from 0 through 32, for example /24.
Select the calculate button to derive the boundaries, masks, host range, and address counts.
Check the values against your network plan, then copy the complete result when you need to document it.
Classless Inter-Domain Routing (CIDR) writes an IP address and network prefix together. In 192.168.1.10/24, the /24 means the first 24 bits identify the network and the remaining 8 bits identify addresses inside that subnet.
A longer prefix creates a smaller subnet. For example, a /24 contains 256 total addresses, while a /28 contains 16.
The network and broadcast values define the usual subnet boundaries. The subnet mask is the dotted-decimal form of the CIDR prefix, while the wildcard mask is its inverse and is commonly used in access-control rules.
Use the calculation as a planning aid, then confirm the assigned prefix with your hosting provider or network administrator before changing a server interface, router, DHCP range, route, or firewall rule. A wrong prefix can interrupt connectivity or create overlapping networks.
FREQUENTLY ASKED QUESTIONS
10.20.30.40/16 is valid. A subnet mask without a CIDR prefix is not accepted in the input./0 through /30, the first address identifies the network and the last is the broadcast address. Hosts normally use the addresses between them./31 is treated as a point-to-point subnet where both addresses can be endpoints and no broadcast address is used. A /32 represents one host route, so its single address is the only usable host.255.255.255.0 has a wildcard mask of 0.0.0.255. Some routers and access-control lists use this format.