🌐 CIDR & IP Subnet Calculator
Calculate IPv4 CIDR blocks, subnet masks, wildcard masks, network and broadcast addresses, and usable IP address ranges online. 100% free.
Quick Presets:
🌐 CIDR Notation-
🔒 Subnet Mask-
📍 Network Address-
📢 Broadcast Address-
🟢 First Usable Host-
🔴 Last Usable Host-
🖥️ Usable Hosts Count-
⚡ Wildcard Mask-
🔢 32-Bit Binary Representation
IP Address Binary:-
Subnet Mask Binary:-
❓ Frequently Asked Questions
What is CIDR notation and how does it work?
CIDR (Classless Inter-Domain Routing) notation represents an IP address and its network mask prefix length (e.g., /24), indicating how many bits belong to the network prefix versus the host bits.
Why are the first and last IP addresses in a subnet reserved?
In IPv4 networking, the very first IP is reserved as the Network Address (identifying the subnet itself), and the last IP is reserved as the Broadcast Address for sending packets to all hosts in that subnet.
Is my network IP information sent to any external server?
No. All bitwise operations, CIDR parsing, binary conversions, and range calculations are executed 100% locally inside your web browser.
