IP Range Calculator
Calculate the start IP, end IP, and number of addresses in an IPv4 range from a CIDR block (e.g. 10.0.0.0/24). Essential for firewall rules, ACLs, and network planning. Free, runs in your browser.
Calculate IP Range
Enter any IPv4 CIDR (e.g. 10.0.0.0/24), then click Get range to see the first and last IP and host counts.
Result
| Normalized CIDR | 192.168.1.0/24 |
|---|---|
| Start IP (network) | 192.168.1.0 |
| End IP (broadcast) | 192.168.1.255 |
| Total addresses | 256 |
| Usable host addresses | 254 |
What Is an IP Range?
An IP range is a contiguous block of IP addresses. It can be described by a start and end address (e.g. 192.168.1.1 to 192.168.1.254) or by a base address and prefix length in CIDR notation (e.g. 192.168.1.0/24). The range defines which addresses belong to the same subnet or allocation. Firewalls, security groups, and access control lists often use IP ranges to allow or deny traffic.
Calculating the exact range from a CIDR block requires bitwise operations: the network address is the first address (all host bits zero), and the broadcast address is the last (all host bits one). Our subnet calculator does this instantly. The network address calculator and broadcast address calculator pages explain these concepts in depth. For host count, see the IP block size calculator.
How to Use the IP Range Calculator
Enter any private or public IPv4 CIDR prefix (e.g. 172.16.0.0/20) into the calculator above and click Get range. You’ll see the normalized CIDR, the first address in the block (network), the last address (broadcast), the total number of addresses, and the number of usable host addresses. If you need to list every single IP — for scripts, firewall configs, or bulk tools — use our IP range generator. Validate IPs before use with the IP address validator or IP list validator for multiple addresses.
Why IP Ranges Matter
Network segmentation, cloud VPC design, and firewall rule creation all depend on knowing exact IP ranges. Overlapping ranges can cause routing or security issues. A clear picture of start, end, and size helps you avoid conflicts and document your network. Pair IP range tools with IP lookup for geolocation, WHOIS lookup for ownership, or ping test and traceroute for connectivity checks.
FAQs
What is an IP range?
An IP range is a set of consecutive IP addresses, often expressed as a start and end address or as a CIDR block (e.g. 192.168.1.0/24).
How do I calculate the IP range from CIDR?
Use our subnet calculator: enter the base IP and CIDR (e.g. /24). It shows the network address (first) and broadcast address (last), and the usable host range in between.
What is the difference between IP range calculator and IP range generator?
An IP range calculator shows the start and end addresses and count for a subnet. An IP range generator lists every single IP in that range for copy-paste or export.
Is the IP range calculator free?
Yes. All our IP calculators run in your browser with no signup.