CIDR Subnet Calculator
Calculate IPv4 CIDR notation subnets, usable host ranges, and broadcast addresses.
CIDR Subnet Calculator
192.168.1.1
/24
254
256
About CIDR Subnet Calculator
The CIDR & IPv4 Subnet Calculator computes Network Address, Broadcast Address, Subnet Mask, Wildcard Mask, Usable Host IP Range, and Total Usable Hosts for any IPv4 CIDR block prefix (`/0` to `/32`) with visual bitmask division.
How to Use CIDR Subnet Calculator
Step 1
Enter an IP address and select a CIDR prefix length (e.g. `/24`, `/16`).
Step 2
Inspect the calculated network boundaries and usable host address range.
Step 3
Review the 32-bit binary network/host bit allocation bar.
Step 4
Click "Copy Subnet Report".
Practical Use Cases for CIDR Subnet Calculator
Cloud VPC & Subnet Architecture (AWS / GCP / Azure)
Plan VPC CIDR blocks (`10.0.0.0/16`) and divide them into isolated public and private subnets (`/24`) without IP overlapping.
Cisco & Enterprise Network Engineering
Calculate subnet masks, wildcard masks, and host capacity for routing protocol configuration (OSPF, BGP, VLANs).
Input & Output Examples
Calculating Subnet for 192.168.1.0/24
CIDR: 192.168.1.0/24
Netmask: 255.255.255.0 | Network: 192.168.1.0 | Broadcast: 192.168.1.255 | Host Range: 192.168.1.1 - 192.168.1.254 | Total Hosts: 254
Key Features & Performance
- ✓Calculates Network IP, Broadcast IP, Netmask, Wildcard Mask, and First/Last Usable Host IP.
- ✓Interactive visual 32-bit binary subnet mask diagram showing Network Bits vs Host Bits.
- ✓Supports all prefix lengths from `/0` (Internet) to `/32` (Single Host).
- ✓100% Client-Side calculation.
- ✓1-Click Copy subnet specification.
Key Terminology & Definitions
CIDR (Classless Inter-Domain Routing)
A method for allocating IP addresses and IP routing using prefix length notation (`/24`) rather than legacy fixed classful boundaries (Class A, B, C).
Wildcard Mask
An inverted subnet mask where 0s indicate required bit matches and 1s indicate ignored bits, used in Cisco ACLs and OSPF configs.