Run high-precision bitwise calculations for IPv4 CIDR blocks and 128-bit IPv6 network subnets with full hex representation.
IP Subnet Calculator - IPv4 & IPv6 CIDR Planner | NetAI
Enter a valid IP address and prefix to compute results.
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Professional IP subnet calculator for network engineers. High-precision bitwise calculation for IPv4 and IPv6. Determine host ranges, mask bits, and broadcast addresses instantly.
subnet calculator, cidr calculator, ip planner, ipv6 subnetting, network mask, broadcast address, host range calculation
Plan your network hierarchy with our advanced IPv4/IPv6 subnetting tool.
Calculate network details, subnets, broadcast addresses, usable host ranges, and wildcard masks for IPv4 and IPv6 CIDR blocks.
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Calculate subnets, CIDR prefixes, wildcard masks, and host availability bounds for IPv4 and IPv6 allocations.
RFC 4632 (CIDR Architecture), RFC 4291 (IPv6 Address Architecture), Cisco IOS, Nokia SROS, Juniper Junos, Huawei VRP
IPv4 (e.g. 192.168.1.0 with /24 prefix) or IPv6 (e.g. 2001:db8:: with /64 prefix)
Network IP, Broadcast IP, Netmask, Range of Usable Host IPs, and Total IP Count
Utilize /31 or /127 prefixes for peer-to-peer WAN connections to avoid IP wastage.
Designate specific address blocks for Infrastructure, Servers, User VLANs, and VPN pools.
Always align subnet layouts to binary power-of-two boundaries to ensure simple route summarization.
Planning corporate IP allocations using Variable Length Subnet Masking (VLSM).
Setting up IP prefixes for virtual networks inside cloud platforms (AWS VPC, Azure VNet).
Determining configuration ranges for access control lists (ACLs) and route maps.
For IPv4 networks, the first IP is the network identifier and the last is the broadcast address. Neither can be allocated to host interfaces.
For IPv6 networks, /64 is standard for end-user LANs due to SLAAC requirements.
The IP Subnet Calculator calculates subnet ranges, network boundaries, and CIDR masks for IPv4 and IPv6. It resolves binary bitmasks to compute host limits and broadcast ranges instantly, offering network engineers a precise mathematical reference for routing configuration.
Use this tool when provisioning local networks, planning cloud VPC ranges, or routing protocols (like OSPF or BGP). It eliminates manual binary arithmetic errors when deploying routers from Cisco, Nokia, or Juniper.
An operations team needs to subdivide a 10.0.0.0/22 network block into separate VLANs for Engineering (200 hosts), Sales (100 hosts), and VoIP (100 hosts). Using the Subnet Calculator, they determine that 10.0.0.0/24 (254 usable hosts) meets the Engineering demand, while 10.0.1.0/25 (126 usable hosts) and 10.0.1.128/25 (126 usable hosts) host Sales and VoIP perfectly without overlapping.
Leave a 20-30% margin for device expansion in local subnets. Implement strict naming conventions and document subnet maps inside a centralized IPAM database to prevent duplicate route conflicts.
Configuring overlapping IP scopes across separate VLANs or VPN endpoints, causing intermediate router conflicts and packet drops. Always double-check your CIDR boundary using this bitwise validator before executing CLI changes.
What is the usable host range in a /24 subnet?
A /24 subnet contains 256 total IP addresses. Since the network ID (first address) and broadcast (last address) are reserved in IPv4, there are 254 usable IPs for hosts.
Why use a /31 subnet for point-to-point links?
Per RFC 3021, a /31 subnet allocates exactly two IP addresses for point-to-point connections, removing the traditional need for a /30 block and preventing the wastage of network and broadcast IPs.
CIDR stands for Classless Inter-Domain Routing. It allows variable-length subnet masks (VLSM) instead of historical Classful (Class A, B, C) address networks.
How many subnets are in a /20 if I split it into /24s?
A /20 block contains 16 individual /24 subnets, calculated as 2^(24-20) = 2^4 = 16.
What is a 'Global Unicast' IPv6 address?
Equivalent to a public IPv4 address, Global Unicast addresses (prefixes starting with 2000::/3) are globally unique and routable on the public internet.
Yes. In modern networking environments, the first subnet (subnet zero) is fully supported and safely configurable on routing platforms without causing issues.
A /24 subnet contains 256 total IP addresses. Since the network ID (first address) and broadcast (last address) are reserved in IPv4, there are 254 usable IPs for hosts.
Per RFC 3021, a /31 subnet allocates exactly two IP addresses for point-to-point connections, removing the traditional need for a /30 block and preventing the wastage of network and broadcast IPs.
CIDR stands for Classless Inter-Domain Routing. It allows variable-length subnet masks (VLSM) instead of historical Classful (Class A, B, C) address networks.