Calculate an IPv4 range from start and end IP addresses. See the inclusive count, samples, hex values, private or public context, special ranges, and CIDR details when applicable.
An IP range calculator answers a practical networking question: which IPv4 addresses lie between two boundaries, and how large is that interval? Enter a start IP and an end IP to see the inclusive address count, range size, class information, private or public range label, hexadecimal boundaries, sample addresses, and any special-range flags detected by the tool.
This page is designed for start-and-end IPv4 analysis. It does not ask for a CIDR prefix or subnet mask as an input, and it does not expand an IPv6 range. That distinction matters when choosing a calculator. A range checker begins with two endpoints; a subnet calculator normally begins with a network address and prefix, then works out the block boundaries and usable hosts.
Enter each address in ordinary dotted-decimal IPv4 format, such as 192.168.1.10 and 192.168.1.20. The first value is the start IP and the second is the end IP. The calculator validates both values before doing the arithmetic, so incomplete octets, letters, IPv6 notation, and other malformed input are rejected. The start address must be numerically less than or equal to the end address; reversing the two values produces an error instead of a misleading negative range.
These two boundaries describe an interval, not automatically a complete network block. A range can begin or end in the middle of a conventional Class A, B, or C space, cross a class boundary, or contain addresses with different practical roles. The class labels shown in the result are legacy IPv4 categories based on the first octet. They are useful for quick context, but modern routing and network planning rely on CIDR boundaries rather than classful labels alone.
Ordering is based on the IPv4 numeric value, not on a text comparison. For example, 192.168.1.9 comes before 192.168.1.100 even though the last octet has fewer digits. That is why the calculator converts the dotted address into a number before counting. When checking a vendor range or a copied configuration, preserve every octet and do not remove leading structure from the address while transcribing it.
The total is calculated inclusively: end - start + 1. For example, the interval from 192.168.1.10 through 192.168.1.20 contains 11 addresses because both endpoints count. This is the number to use when checking the size of an allowlist, documenting a DHCP scope, estimating test addresses, or reviewing a group of entries. It is not automatically a usable-host count, because the tool does not remove network, broadcast, gateway, or reserved addresses from the total.
For a small interval, the result can show every address. For a larger interval, it shows the first five and last five with an ellipsis so the page remains readable instead of attempting to print thousands or millions of values. The hexadecimal start and end values provide a second way to compare IPv4 boundaries when you are reading firewall rules, logs, binary-oriented documentation, or software output. They represent the same addresses; they are not additional addresses in the range.
CIDR notation is a compact description of a network block, such as a prefix followed by a slash length. A correctly aligned IPv4 block contains a power-of-two number of addresses, and its first address must fall on the boundary implied by that prefix. A range of 192.168.1.0 through 192.168.1.255 is a familiar 256-address block, commonly written as a /24. A four-address block can be represented as /30 when its start is aligned correctly.
When the entered range has a power-of-two size, this tool displays CIDR-related information when available: a prefix length, subnet mask, network value, and broadcast value. Use those fields as a quick block check, and confirm that the start boundary is aligned before placing the result into a router, firewall, or cloud rule. A non-power-of-two interval is still a valid start-to-end range, but it cannot be represented by one exact CIDR block without including addresses outside the requested boundaries. That is why this calculator should not be treated as a full CIDR decomposition tool.
The distinction from a subnet calculator is important in day-to-day work. A subnet calculator usually starts with an address and prefix such as a network block, then derives its boundaries and host capacity. This page starts with the boundaries you already have and tells you what they contain. If you need to split a network into smaller subnets, calculate wildcard masks, or plan multiple prefixes, use a dedicated subnetting workflow rather than assuming one range result answers those questions.
Network administrators can use a start/end calculation to review a device pool, check a proposed firewall allowlist, document a migration window, compare a vendor-provided address interval, or confirm that a test plan covers the intended IPv4 values. Developers can use the count and samples while validating parsers, access-control rules, monitoring filters, or configuration generators. The result is also useful when a support ticket gives two endpoints but does not state the CIDR notation.
Read the range type carefully. The tool checks the well-known private IPv4 spaces 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 at the endpoints. A range whose endpoints are both private is labelled private; other cases are labelled public or mixed, so do not treat that label as a complete registry or security classification. The page can also flag loopback, link-local/APIPA, multicast, or the all-ones broadcast address when its simple checks detect them. These flags are clues for review, not proof that an address is safe, routable, or assignable.
For an address list, the sample output is a sanity check rather than a downloadable inventory. It lets you confirm the beginning and end of a large interval without filling the page with every member. If a policy needs exact entries, generate or review that list in the system that will enforce it, then compare its first and last values with this result. This is especially useful when a typo would silently widen a security rule.
Keep three limitations in mind before acting on the result. The calculator accepts IPv4 start and end values only, it does not calculate IPv6 ranges, and it does not decide which addresses your network may legally or operationally assign. It also does not test reachability, reserve addresses, query routing tables, or verify a firewall policy. For troubleshooting, compare the displayed boundaries and count with the source configuration, then check the network and broadcast roles separately. That small verification step prevents a correct arithmetic result from becoming an incorrect production rule.