Pure Frontend · CIDR Subnet Calculation · Subnet Split · Available IP Stats
Zero Dependencies · Works OfflineWhat Can the Subnet Divider Do?
The Subnet Divider is a pure frontend online tool for IPv4 CIDR subnet calculation and splitting. Enter a CIDR address to get network address, broadcast address, subnet mask, available IP range and count. It also supports splitting a large network into a specified number of smaller subnets. All calculations happen locally in the browser.
Core Features
- CIDR Parsing: Enter CIDR address, auto-calculate network, broadcast, and subnet mask
- Available IP Stats: Calculate available host IP count and range
- Subnet Split: Divide a large network into specified number of smaller subnets
- Binary Display: Show IP and mask in binary representation
- One-Click Copy: Copy results or download as text
How to Use
Step 1: Enter CIDR address like 192.168.1.0/24.
Step 2: Click "Calculate" to view subnet details.
Step 3: To split, enter target subnet count and click "Split".
Step 4: View split results, copy or download.
Use Cases
Network Planning
Network engineers plan enterprise IP allocation, dividing subnets to avoid IP waste.
Ops Configuration
Ops teams need precise subnet ranges when configuring firewall rules and routing tables.
Cloud Computing
Calculate CIDR ranges when creating subnets in AWS VPC, Azure VNet, etc.
Education
Networking students practice subnet division and verify manual calculations.
Extended Knowledge
CIDR (Classless Inter-Domain Routing) replaced traditional A/B/C class network classification with variable-length prefixes for flexible address allocation. CIDR notation IP/prefix_length indicates the number of network bits. For example, /24 means 24 network bits and 8 host bits, accommodating 2^8-2=254 hosts. Subnet mask is another representation: /24 = 255.255.255.0. VLSM (Variable Length Subnet Mask) allows different-sized subnets within the same network for better address utilization.
FAQ
What is CIDR notation?
CIDR notation like 192.168.1.0/24, where /24 means the first 24 bits are network bits and the last 8 are host bits, accommodating 254 hosts.
How to calculate available IPs?
Available IPs = 2^(32-prefix length)-2, subtracting network and broadcast addresses. E.g., /24 has 2^8-2=254 available IPs.
Is IPv6 supported?
Current version only supports IPv4. IPv6 support will be added in a future version.
Is data uploaded to a server?
No. All calculations happen locally in the browser.
How to split a large network?
Enter CIDR address and target subnet count. The tool calculates the split showing each subnet's details.
How to convert subnet mask and CIDR prefix?
/24 = 255.255.255.0, /16 = 255.255.0.0, /8 = 255.0.0.0. The tool shows the correspondence automatically.