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IP Range CalculatorPRO
IPv4 Subnetting & RangeInstant Client-Side Tool

Network Address Calculator

Find the subnet’s network address.

Network Address Calculator: inputs and results

Enter an IP address, CIDR prefix, or range. Then check its first and last address below.

Quick presets:

Calculated Boundaries & ParametersReady

Network Address192.168.1.0
Broadcast Address192.168.1.255
First Usable Host192.168.1.1
Last Usable Host192.168.1.254
Subnet Mask255.255.255.0
Wildcard Mask0.0.0.255
Total Addresses256
Usable Host Range254

Key Capabilities

  • •100% Client-Side: Zero telemetry or server latency.
  • •RFC Compliant: Exact 32-bit and 128-bit integer precision.
  • •Quick Copy: Instant access to CIDR, mask, and range bounds.
  • •Cross-Platform: Works on desktop, tablet, and mobile browsers.
Open Full Interactive Suite

Related IPv4 Subnetting & RangeAll Tools

IPv4 Range Calculator

Find address boundaries from a prefix.

IPv4 Subnet Calculator

Calculate subnet details from address and mask.

IPv4 Broadcast Address Calculator

Find broadcast addresses where applicable.

First and Last Address Calculator

Identify a range’s endpoints.

Usable IPv4 Host Range Calculator

Apply the selected subnet-use rules.

Total Address Count Calculator

Count addresses within a prefix.

How Network Address Calculator Works?

This tool works by performing a bitwise AND between the IPv4 address and the subnet mask. Every bit where the mask is 1 is copied from the address, and every bit where the mask is 0 becomes 0.

  1. Enter any host address

    Any address inside the subnet works. 172.16.45.130, 172.16.45.150, and 172.16.45.190 all return the same /26 network.

  2. Choose the prefix or mask

    Enter /26 or 255.255.255.192. Both describe 26 network bits and 6 host bits.

  3. Apply the AND operation

    The calculator runs address AND mask on the 32-bit integer form of both values.

  4. Return the network ID

    The result, 172.16.45.128, is the network address used in routing tables and route advertisements.

Network Address Calculator Formula

The formula is Network Address = IP Address AND Subnet Mask. A shortcut works on the one octet where the mask is neither 255 nor 0.

Bitwise rule

N = IP AND Mask

Applied to all 32 bits at once.

Octet shortcut

N_octet = floor(IP_octet ÷ Block) × Block

Block = 256 − mask octet. Octets left of it are copied and octets right of it become 0.

Integer form

N = floor(IP_int ÷ 2^(32−p)) × 2^(32−p)

Rounds the 32-bit integer down to the nearest multiple of the block size.

Worked example: 172.16.45.130/26

Mask 4th octet = 192 → Block = 256 − 192 = 64
130 ÷ 64 = 2.03 → floor = 2 → 2 × 64 = 128
Binary check: 10000010 AND 11000000 = 10000000 = 128
Network address = 172.16.45.128

Network Address Calculator Conversion Table

The table shows the network address of 172.16.45.130 for 13 prefix lengths, with the matching subnet mask and the network address in hexadecimal.

PrefixSubnet MaskNetwork AddressNetwork (Hex)
/8255.0.0.0172.0.0.00xAC000000
/12255.240.0.0172.16.0.00xAC100000
/16255.255.0.0172.16.0.00xAC100000
/18255.255.192.0172.16.0.00xAC100000
/20255.255.240.0172.16.32.00xAC102000
/22255.255.252.0172.16.44.00xAC102C00
/24255.255.255.0172.16.45.00xAC102D00
/25255.255.255.128172.16.45.1280xAC102D80
/26255.255.255.192172.16.45.1280xAC102D80
/27255.255.255.224172.16.45.1280xAC102D80
/28255.255.255.240172.16.45.1280xAC102D80
/29255.255.255.248172.16.45.1280xAC102D80
/30255.255.255.252172.16.45.1280xAC102D80

What is Network Address Calculator?

The Network Address Calculator is a tool that finds the network address (network ID) of the subnet that contains a given IPv4 address. The network address is the lowest address in a subnet, with every host bit set to 0.

Routers store routes by network address and prefix length, such as 172.16.45.128/26. Hosts compare their own network address with the network address of a destination to decide whether traffic stays local or goes to the default gateway.

The Network Address Calculator returns only the network ID, which keeps the output focused for route entries, Access Control List (ACL) statements, and Open Shortest Path First (OSPF) network commands.

What are the uses of Network Address Calculator?

There are 5 main uses of the Network Address Calculator, including route configuration, ACL writing, and subnet identification.

  • Writing static routes

    A static route requires the network address, not a host address. ip route 172.16.45.128 255.255.255.192 is valid and 172.16.45.130 is rejected on most platforms.

  • Configuring OSPF and EIGRP

    Routing protocol network statements reference the network address with a wildcard or mask.

  • Building ACL entries

    ACLs match traffic by network address and wildcard. The calculator gives the base address for each entry.

  • Grouping hosts by subnet

    Inventory scripts group thousands of host addresses by their network address to show which subnet each device sits in.

  • Verifying IPAM records

    IP Address Management (IPAM) tools store subnets by network ID. The calculator confirms that a recorded subnet starts on a valid boundary.