IP / CIDR Calculator
Calculate subnets, network ranges, and CIDR notation. Supports IPv4 and basic IPv6.
Accepts: IP/CIDR, IP/subnet-mask, or bare IP address
Calculated Results
Binary Representation
Subnet Bit Breakdown
What is an IP Subnet Calculator?
An IP subnet calculator divides a network into smaller subnetworks by computing network addresses, broadcast addresses, usable host ranges, and subnet masks from CIDR notation (e.g., 192.168.1.0/24). Subnetting is essential for network design, security segmentation, and efficient IP address allocation in both on-premises and cloud environments.
Common Use Cases
- •Planning VPC subnets in AWS, GCP, or Azure
- •Calculating usable host ranges for network segments
- •Determining if two IP addresses are on the same subnet
- •Dividing a network into smaller subnets for security zones
- •Troubleshooting network connectivity issues
Frequently Asked Questions
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation represents a network as an IP address followed by a slash and the number of network bits, like 192.168.1.0/24. The /24 means the first 24 bits are the network portion, leaving 8 bits (256 addresses, 254 usable) for hosts.
How many usable hosts does a /24 network have?
A /24 network has 256 total addresses (2^8), but 2 are reserved: the network address (.0) and broadcast address (.255). So 254 usable host addresses. In general, usable hosts = 2^(32-prefix) - 2.