What is an IP calculator?
An IP calculator is a networking tool used to analyze an IPv4 address together with a subnet mask or CIDR prefix. It determines the network that contains the address and calculates important values such as the network address, broadcast address, subnet mask, wildcard mask, usable host range and number of addresses in the subnet.
This information is useful when configuring devices, assigning IP addresses, designing VLANs, troubleshooting connectivity, planning networks or studying IPv4 addressing and subnetting.
How does an IPv4 address work?
An IPv4 address contains 32 binary bits. It is normally displayed as four decimal values separated by periods, such as 192.168.1.10. Each decimal value represents eight bits and can range from 0 to 255.
An IPv4 address by itself does not tell you where the network ends and the host portion begins. That boundary is defined by a subnet mask or CIDR prefix.
What is a subnet mask?
A subnet mask separates the network portion of an IPv4 address from the host portion. For example, the subnet mask 255.255.255.0 means that the first 24 bits identify the network and the final 8 bits are available for addresses inside that network.
The same subnet mask can also be written using CIDR notation as /24. Both forms describe the same IPv4 network boundary.
What is CIDR?
CIDR stands for Classless Inter-Domain Routing. CIDR notation uses a slash followed by a prefix length, such as /24 or /28, to indicate how many of the 32 IPv4 bits belong to the network portion.
Larger prefix values produce smaller subnets because more bits are reserved for the network. For example, a /24 contains 256 total IPv4 addresses, while a /28 contains only 16.
How does the IP calculator work?
The calculator first converts the IPv4 address and subnet mask into their 32-bit binary forms. It performs a bitwise operation between the address and subnet mask to determine the network address.
The inverse of the subnet mask forms the wildcard mask. Combining the network address with the wildcard mask determines the final address in the subnet, commonly called the broadcast address.
The remaining host bits determine the total number of addresses available within the network. For traditional IPv4 subnets, the network and broadcast addresses are normally excluded when calculating usable host addresses.
How to use this IP calculator
- Enter an IPv4 address such as 192.168.1.10.
- Choose whether you want to use a CIDR prefix or subnet mask.
- Enter the prefix, such as /24, or the equivalent subnet mask, such as 255.255.255.0.
- Alternatively, enter the IP and CIDR together as 192.168.1.10/24.
- Click Calculate IP.
- Review the network address, broadcast address, usable host range, mask information and address capacity.
Understanding the IP calculator results
Network Address
The network address identifies the IPv4 subnet itself. In a traditional subnet it is normally the first address in the range and is not assigned to an ordinary device.
Broadcast Address
The broadcast address is normally the final address in an IPv4 subnet. It traditionally represents communication intended for all hosts on that subnet.
Subnet Mask
The subnet mask defines how many IPv4 bits belong to the network portion and how many remain available for hosts.
Wildcard Mask
The wildcard mask is the inverse of the subnet mask and is commonly used in network access control and routing configurations.
First and Last Host
These values identify the traditional usable host range between the network address and broadcast address. /31 and /32 prefixes have special behavior.
Total Addresses
The total address count includes every IPv4 address within the subnet, including network and broadcast addresses where applicable.
Usable Hosts
The usable host count estimates the addresses normally assignable to hosts within the subnet. Traditional IPv4 networks usually reserve the network and broadcast addresses.
Address Type
The calculator identifies whether the entered IPv4 address belongs to a common private, public, loopback, link-local, multicast or other special-use range.
IP calculation example
Consider the IPv4 address 192.168.1.10 with a /24 prefix. The /24 prefix corresponds to the subnet mask 255.255.255.0.
The resulting network begins at 192.168.1.0 and ends at 192.168.1.255. In a traditional /24 subnet, usable host addresses range from 192.168.1.1 through 192.168.1.254.
Private IPv4 address ranges
Private IPv4 addresses are intended for use inside local networks and are not routed directly across the public Internet. Three commonly used private IPv4 blocks are defined.
| Private Address 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
What does an IP calculator calculate?
An IP calculator uses an IPv4 address together with a CIDR prefix or subnet mask to calculate the network address, broadcast address, subnet mask, wildcard mask, host range and address capacity.
Can I enter an IP address with CIDR notation?
Yes. You can enter an IPv4 address such as 192.168.1.10/24 directly into the calculator.
What is the difference between an IP calculator and a subnet calculator?
The tools overlap, but an IP calculator focuses on analyzing a specific IPv4 address within its network, while a subnet calculator focuses more broadly on the properties and boundaries of the subnet.
What subnet is 192.168.1.10/24 in?
192.168.1.10/24 belongs to the network 192.168.1.0/24. Its traditional broadcast address is 192.168.1.255.
Is 192.168.1.10 a private IP address?
Yes. 192.168.1.10 belongs to the private IPv4 block 192.168.0.0/16.
Does the calculator support /31 and /32?
Yes. /31 networks are commonly used for point-to-point links, while /32 represents a single IPv4 address or host route.