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IP Range CalculatorPRO
IPv4 Subnetting & RangeInstant Client-Side Tool

IPv4 Broadcast Address Calculator

Find broadcast addresses where applicable.

IPv4 Broadcast 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.

Network Address Calculator

Find the subnet’s network address.

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 IPv4 Broadcast Address Calculator Works?

This tool works by setting every host bit of the network address to 1 with a bitwise OR against the wildcard mask. Prefixes /31 and /32 return no broadcast address.

  1. Enter the address and prefix

    Type 203.0.113.77/28 or an address with a dotted mask.

  2. Find the network address

    The calculator runs IP AND mask to get 203.0.113.64.

  3. Build the wildcard mask

    The wildcard is the bitwise inverse of the mask. A /28 has the wildcard 0.0.0.15.

  4. OR network with wildcard

    203.0.113.64 OR 0.0.0.15 gives 203.0.113.79, the directed broadcast address of the subnet.

IPv4 Broadcast Address Calculator Formula

The formula is Broadcast = Network Address OR Wildcard Mask, which equals the network address plus the block size minus 1.

Bitwise rule

B = (IP AND Mask) OR (NOT Mask)

All host bits become 1.

Additive rule

B = Network + 2^(32−p) − 1

For a /28: Network + 16 − 1 = Network + 15.

Next-subnet rule

B = Next Network − 1

The broadcast address sits 1 below the start of the following subnet.

Exception

/31 and /32 → no broadcast

RFC 3021 removes the broadcast on /31 links, and a /32 holds 1 address.

Worked example: 203.0.113.77/28

Block size  = 2^(32−28) = 16
Network     = 203.0.113.64   (77 rounded down to a multiple of 16)
Wildcard    = 0.0.0.15
Broadcast   = 64 OR 15 = 79  → 203.0.113.79
Check       = next subnet 203.0.113.80 − 1 = 203.0.113.79

IPv4 Broadcast Address Calculator Conversion Table

The table shows the wildcard mask and broadcast address of 203.0.113.77 for prefixes /20 to /32, with the broadcast written as a decimal integer.

PrefixWildcard MaskBroadcast AddressBroadcast (Integer)
/200.0.15.255203.0.127.2553,405,807,615
/210.0.7.255203.0.119.2553,405,805,567
/220.0.3.255203.0.115.2553,405,804,543
/230.0.1.255203.0.113.2553,405,804,031
/240.0.0.255203.0.113.2553,405,804,031
/250.0.0.127203.0.113.1273,405,803,903
/260.0.0.63203.0.113.1273,405,803,903
/270.0.0.31203.0.113.953,405,803,871
/280.0.0.15203.0.113.793,405,803,855
/290.0.0.7203.0.113.793,405,803,855
/300.0.0.3203.0.113.793,405,803,855
/310.0.0.1None (no broadcast)—
/320.0.0.0None (no broadcast)—

What is IPv4 Broadcast Address Calculator?

The IPv4 Broadcast Address Calculator is a tool that finds the directed broadcast address of an IPv4 subnet, the last address in the block with every host bit set to 1. A packet sent to that address reaches every host on the subnet.

IPv4 defines 2 broadcast types. The limited broadcast 255.255.255.255 stays on the local link. The directed broadcast, such as 203.0.113.79 for 203.0.113.64/28, targets one specific subnet. The calculator returns the directed broadcast.

IPv6 has no broadcast address and uses multicast groups. The calculator therefore covers IPv4 only, and it marks /31 point-to-point links and /32 host routes as having no broadcast address.

What are the uses of IPv4 Broadcast Address Calculator?

There are 5 main uses of the IPv4 Broadcast Address Calculator, including interface checks, Wake-on-LAN setup, and security hardening.

  • Avoiding invalid host assignments

    The broadcast address cannot be assigned to a host. The calculator shows which address to skip during static addressing.

  • Configuring Wake-on-LAN

    Wake-on-LAN magic packets are often sent to the directed broadcast of the target subnet.

  • Hardening against Smurf attacks

    Routers block directed broadcasts with no ip directed-broadcast. The calculator lists the exact addresses to filter.

  • Reading packet captures

    Traffic to a .79, .127, or .255 address is not always broadcast. The calculator confirms whether a destination is the broadcast of its subnet.

  • Setting legacy application targets

    Older discovery and NetBIOS tools send queries to the subnet broadcast. The calculator supplies the correct target address.