What is an IP range calculator?
An IP range calculator is a networking tool that determines how many IPv4 addresses exist between a starting IP address and an ending IP address. It can be useful when planning address pools, documenting network ranges, reviewing DHCP assignments or checking how large a particular IPv4 block is.
For example, the range from 192.168.1.1 to 192.168.1.254 contains 254 IPv4 addresses. The calculator converts each dotted-decimal IPv4 address into its numeric value, calculates the difference and then includes both the starting and ending addresses in the final count.
What is an IPv4 address range?
An IPv4 address range is a continuous sequence of IP addresses beginning with one address and ending with another. A range can represent a group of addresses assigned to devices, a DHCP pool, a portion of a subnet, an allowlist or another block of addresses used for network administration.
The start address must occur before or be equal to the end address. Because IPv4 addresses are numerical values internally, even ranges that cross an octet boundary can be counted accurately.
How does the IP range calculator work?
An IPv4 address contains four decimal octets, such as 192.168.1.10. Each octet represents eight bits, so the complete address contains 32 bits. The calculator converts the starting and ending addresses into 32-bit numeric values.
It then subtracts the numeric value of the first address from the last address and adds one so that both boundary addresses are included. This provides the exact number of IPv4 addresses in the selected range.
How to use the IP range calculator
- Enter the first IPv4 address in the range, for example 192.168.1.1.
- Enter the final IPv4 address, for example 192.168.1.254.
- Click Calculate IP Range.
- Review the normalized start and end addresses and the total number of IPv4 addresses in the range.
- Use the Copy buttons if you need to paste the calculated values into documentation, configuration notes or another tool.
IP range calculation example
Suppose the starting address is 192.168.10.100 and the ending address is 192.168.10.150. Because the range includes both the first and last addresses, it contains 51 total IPv4 addresses.
IP range vs subnet
An IP range and an IP subnet are related concepts, but they are not always the same thing. An IP range simply describes a continuous block between a starting and ending address. It does not need to follow a CIDR boundary.
A subnet, on the other hand, is defined by a network address and subnet mask or CIDR prefix. Subnets have mathematically defined boundaries determined by their prefix length.
For example, 192.168.1.20 through 192.168.1.80 is a valid IP range, but it is not itself a standard CIDR subnet. If you need network and broadcast addresses from a CIDR prefix, use the Subnet Calculator instead.
Common uses for an IP range calculator
DHCP address pools
Count how many IPv4 addresses are available between the starting and ending addresses of a DHCP allocation range.
Network documentation
Confirm the size of address blocks listed in network diagrams, inventories and configuration records.
Firewall and access rules
Check the number of addresses covered by a continuous IPv4 range before documenting an allow or deny rule.
IP address planning
Compare candidate IPv4 blocks when allocating addresses to devices, servers, VLANs or other network segments.
Private IPv4 address ranges
Private IPv4 addresses are commonly used inside local networks and are not routed directly across the public Internet. The calculator can be used with private addresses as well as other valid IPv4 addresses.
| Private Range | CIDR Block |
|---|---|
| 10.0.0.0 – 10.255.255.255 | 10.0.0.0/8 |
| 172.16.0.0 – 172.31.255.255 | 172.16.0.0/12 |
| 192.168.0.0 – 192.168.255.255 | 192.168.0.0/16 |
Frequently asked questions
How do I calculate the number of IP addresses in a range?
Convert the starting and ending IPv4 addresses to their numeric values, subtract the start value from the end value and add one. Adding one ensures that both the first and last IP addresses are included.
Does the IP range calculator include the start and end addresses?
Yes. The total address count includes both the starting IP address and the ending IP address.
Can an IP range cross an octet boundary?
Yes. A range such as 192.168.1.250 through 192.168.2.10 is valid as long as the ending IPv4 address is numerically greater than the starting address.
Is an IP range always a subnet?
No. Any continuous sequence of IPv4 addresses can be described as a range, while a subnet must follow boundaries defined by a valid subnet mask or CIDR prefix.
Can I use this calculator for private IP addresses?
Yes. You can calculate ranges within private IPv4 blocks such as 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.
Does this calculator support IPv6?
This version is designed for IPv4 address ranges. IPv6 uses 128-bit addressing and should be handled with a dedicated IPv6 range or prefix calculator.