IPv4 Subnet Calculator
Your data never leaves your browserCalculate network address, broadcast, subnet mask, host range, and usable hosts from CIDR notation.
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About IPv4 Subnet Calculator
Enter an IPv4 address in CIDR notation (e.g. 192.168.1.0/24) and instantly calculate the network address, broadcast address, subnet mask, wildcard mask, first and last usable host, and total number of addresses. All calculations are done locally in your browser using bitwise operations.
How to use
- Enter an IPv4 address in CIDR notation into the input field (e.g. 192.168.1.100/24).
- Click Convert to see network address, broadcast address, subnet mask, usable host range, and host counts.
- Click Copy to use the results in documentation or configuration.
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Frequently Asked Questions
FAQs about IPv4 Subnet Calculator
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation combines an IP address with a prefix length (e.g. /24). The prefix length indicates how many bits are used for the network portion, with the remaining bits used for hosts.
What is a subnet mask?
A subnet mask is a 32-bit number that separates the network portion of an IP address from the host portion. For /24, the mask is 255.255.255.0.
What is the broadcast address?
The broadcast address is the last address in a subnet. Packets sent to this address are delivered to all hosts on the subnet.
How many usable hosts does a /24 subnet have?
A /24 subnet has 256 total addresses (2^8). Subtracting the network address and broadcast address leaves 254 usable host addresses.
What is a wildcard mask?
A wildcard mask is the inverse of the subnet mask. It is used in access control lists (ACLs) and routing protocols to specify ranges of IP addresses.