How to Use This Subnet Calculator

• IP Address: Enter the network IP (e.g., 192.168.1.0).
• Current Mask: Enter either CIDR format (e.g., 24) or dotted decimal mask (e.g., 255.255.255.0).
• New Mask (optional): Enter a new subnet mask if you want to split the network into smaller subnets (e.g., 25). Leave empty for normal network info.
• Click Calculate to view network details.
• If New Mask is provided, the calculator will generate a detailed card for each resulting subnet, showing network, first/last host, broadcast, total hosts, wildcard mask, IP class, and binary representation.
• All calculations are done client-side — nothing is sent to a server, so your data stays private.

Tip: For large networks split into many subnets, scroll down to see all results.