CIDR / Subnet Calculator
A CIDR calculator turns a block like 192.168.1.0/24 into concrete networking facts: the network and broadcast addresses, subnet mask, and the range of usable host IPs. Toolverge computes this instantly in your browser using standard bitwise subnet math.
How it works
- Enter an IPv4 address with a CIDR prefix, like 192.168.1.0/24.
- The calculator derives the subnet mask from the prefix length, then computes the network and broadcast addresses.
- Read the usable host range and total address count on the tape below.
Formula Subnet mask = 32 - prefix bits; network = IP AND mask; broadcast = network OR (NOT mask).
Frequently asked questions
What does /24 mean in a CIDR block?
/24 means the first 24 bits are the network portion, leaving 8 bits (256 addresses, 254 usable hosts) for the host portion.
Why are only 254 hosts usable in a /24 network?
The first address is the network address and the last is the broadcast address; neither can be assigned to a host.
What happens with a /31 or /32?
A /31 is treated as a 2-host point-to-point link per RFC 3021, and a /32 identifies a single host with no separate network/broadcast split.
Does this support IPv6?
No, this calculator is IPv4-only.
Is my IP address sent anywhere?
No. All subnet math runs locally in your browser.