# IP Subnet Calculator

> Calculate IP range, subnet mask, and available hosts from a CIDR network address.

**Category:** Dev
**Keywords:** ip, subnet, cidr, network, mask, calculator, admin
**URL:** https://complete.tools/subnet-calculator

## How it calculates

The Subnet Calculator uses the following steps to perform its calculations. Given an IP address in the form of A.B.C.D and a subnet mask in the form of E.F.G.H, the calculations are performed as follows: 
1. Convert both the IP address and subnet mask to binary form. 
2. The 'network address' is calculated by performing a bitwise AND operation between the IP address and the subnet mask: 
   Network Address = IP Address × Subnet Mask (in binary)
3. The 'broadcast address' is calculated by performing a bitwise OR operation between the network address and the inverted subnet mask: 
   Broadcast Address = Network Address + (Inverted Subnet Mask)
4. The range of valid hosts is determined by taking the network address and adding 1 to get the first usable IP and taking the broadcast address and subtracting 1 to get the last usable IP. 
These calculations ensure that the network is efficiently segmented.

## Who should use this

Network engineers designing and implementing subnetting strategies for corporate networks. IT administrators managing IP address allocation for large organizations. Cybersecurity professionals analyzing network traffic patterns by segmenting networks into subnets. Educators teaching networking concepts and practices in advanced computer science courses.

## Worked examples

Example 1: Given an IP address of 192.168.1.10 and a subnet mask of 255.255.255.0. First, convert the subnet mask to binary, which is 11111111.11111111.11111111.00000000. The network address is found by performing a bitwise AND operation: 192.168.1.10 AND 255.255.255.0 gives 192.168.1.0. The broadcast address is calculated by taking the inverted subnet mask (0.0.0.255) and performing a bitwise OR with the network address, resulting in 192.168.1.255. The valid host range is from 192.168.1.1 to 192.168.1.254. 

Example 2: For an IP address of 10.0.0.5 with a subnet mask of 255.0.0.0, the network address is 10.0.0.0, and the broadcast address is 10.255.255.255. The valid host range is from 10.0.0.1 to 10.255.255.254. This example illustrates subnetting in a Class A network.

## Limitations

The Subnet Calculator may have limitations such as: 
1. It only supports IPv4 addresses and subnet masks, not IPv6. 
2. If the subnet mask is incorrectly formatted or invalid, the calculations will yield erroneous results. 
3. The tool assumes that the input IP address belongs to the specified subnet mask; results may be inaccurate if this assumption is violated. 
4. The calculator does not account for reserved IP addresses, such as those used for network and broadcast addresses, which may affect available host counts.

## FAQs

**Q:** How does the Subnet Calculator handle CIDR notation?


**A:** The Subnet Calculator converts CIDR notation (e.g., /24) into a subnet mask by determining the number of bits set to 1.


**Q:** Can the tool calculate subnets for multiple IP addresses at once?


**A:** The tool is designed for single IP address calculations; multiple addresses require separate inputs.


**Q:** What happens if I enter a subnet mask that does not correspond to a valid network?


**A:** The calculator will either return an error or output incorrect results, as it relies on valid inputs for accurate calculations.


**Q:** How does the tool determine the number of valid hosts in a subnet?


**A:** The number of valid hosts is calculated using the formula (2^(number of host bits)) - 2, where 'host bits' are derived from the subnet mask.

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*Generated from [complete.tools/subnet-calculator](https://complete.tools/subnet-calculator)*