IP Subnet Calculator – Calculate Network, Broadcast, and Host Ranges
About the IP Subnet Calculator
The IP Subnet Calculator takes any IPv4 address and CIDR prefix length and instantly returns the full subnet breakdown: network address, broadcast address, usable host range, subnet mask, wildcard mask, IP class, and address type. A binary breakdown is included so you can see exactly how the address, mask, and network bits line up bit by bit.
It’s built for network administrators, students studying for certification exams, and developers configuring firewall rules, VPCs, or DHCP scopes who need a fast, accurate way to plan IP address ranges without manual binary math. If you’re troubleshooting connectivity on a domain rather than a raw IP, the DNS Lookup tool is useful for checking how a hostname resolves before you subnet the network behind it.
Once your network ranges are mapped out, the SSL Checker is a natural next step for verifying certificate validity on any public-facing hosts within that range.
Our team tested this calculator across Class A, B, and C networks, edge cases like /31 and /32 prefixes, and private, public, and multicast address ranges to confirm every calculated field matched standard subnetting references.
How to Use the IP Subnet Calculator
- Enter a valid IPv4 Address, such as 192.168.1.100.
- Select the CIDR Prefix Length from the dropdown, shown alongside its equivalent subnet mask.
- Review the results grid for the Network Address, Broadcast Address, First/Last Usable Host, and total and usable host counts.
- Check the Subnet Mask, Wildcard Mask, IP Class, and Address Type fields for additional network details.
- Expand the Binary Breakdown to see the IP address, subnet mask, and network address in raw binary form.
- Use Copy Summary to grab the full breakdown as text, or Clear All to reset the form.
Example Usage
Input: IPv4 Address = 192.168.1.100, CIDR = /24 (255.255.255.0)
Output: Network Address = 192.168.1.0, Broadcast Address = 192.168.1.255, Usable Host Range = 192.168.1.1 – 192.168.1.254, Usable Hosts = 254
Changing the CIDR to /26 on the same IP address recalculates everything instantly: Network Address becomes 192.168.1.64, Broadcast Address becomes 192.168.1.127, and Usable Hosts drops to 62, showing exactly how a smaller subnet shrinks the available host range.
Frequently Asked Questions
The network address identifies the subnet itself and can’t be assigned to a device, while the first usable host is the next address after it, the lowest IP within the range that can actually be assigned to a device.
A /32 identifies a single host with no separate network or broadcast address, and a /31 is a special case used for point-to-point links where both addresses in the pair are usable, since there’s no room for a distinct broadcast address.
The wildcard mask is the inverse of the subnet mask, commonly used in access control lists and routing configurations on network devices like Cisco routers, where a 0 bit means “must match” and a 1 bit means “don’t care.”
Private ranges include 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16, and this calculator automatically flags an entered address as Private, Public, Loopback, Link-Local, or another reserved type based on its first octets.
Yes, it’s fully browser-based with no signup required, and all calculations happen instantly without submitting your data anywhere.
