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/ip address  →  subnet calculator

Calculate any IP subnet
instantly

Network address, broadcast, usable host range, wildcard mask, and CIDR/mask conversion — updated live as you type. Includes a subnet splitter and ready-to-use MikroTik syntax.

Free, no signup Runs 100% in your browser Nothing you type is sent anywhere IPv4 · CIDR /0–/32
Subnet

Enter any IPv4 address and prefix length — it doesn't need to be the network address itself, results are calculated either way.

Subnet splitter (optional)
Results
MikroTik RouterOS syntax

What each result means

Every value updates live as you type — here's what each one actually represents and why it matters.

Network address

The IP with every host bit set to zero — identifies the subnet itself, not any specific device on it.

For beginners: this is the address you'd reference when configuring routes or firewall rules for the whole subnet — it's never assigned to an actual device.

Broadcast address

The IP with every host bit set to one — used to send a packet to every device on the subnet at once.

For beginners: like the network address, this one is reserved and can't be assigned to a device either — assigning it by mistake is a common cause of "why can't this host connect" issues.

Usable host range

Every address between the network and broadcast address — the ones you can actually assign to devices.

For a /24, that's 254 addresses. For a /30 (common on point-to-point links), that's just 2.

Subnet mask / Wildcard

The mask defines which bits are network vs host. The wildcard is its exact inverse, used in access-list and OSPF configuration on some platforms.

For beginners: CIDR notation (/24) and dotted-decimal notation (255.255.255.0) describe exactly the same thing — this tool shows both so you can use whichever your platform expects.

Total vs usable addresses

Total addresses is every address in the block. Usable is total minus 2 (network and broadcast) — except for /31 and /32, which are special cases.

A /31 (RFC 3021) has no network/broadcast concept and both addresses are usable — common on point-to-point links to save address space.

RouterOS syntax

A ready-to-paste /ip address add line using your calculated values, for direct use on a MikroTik router.

Note on IPv6: this calculator handles IPv4 only. IPv6 subnetting uses the same CIDR concept but different address sizes and conventions — a separate calculator would be needed for that.

Want the full explanation of how subnetting works, with worked math? Read the full subnetting guide — covers CIDR notation, binary math for network/broadcast calculation, and common mistakes.

Example output

What the calculator shows for 192.168.1.0/24 — a typical small-office or single-sector subnet.

Network address
192.168.1.0
Broadcast address
192.168.1.255
Subnet mask
255.255.255.0
Wildcard mask
0.0.0.255
First usable host
192.168.1.1
Last usable host
192.168.1.254
Usable hosts
254
Total addresses
256

Frequently asked questions

How do I calculate the network and broadcast address of a subnet?

Enter an IP address and a CIDR prefix (like /24) in the calculator above. The network address is the IP with all host bits set to zero, and the broadcast address is the same IP with all host bits set to one — both are calculated automatically as you type.

What does /24 mean in an IP address?

/24 is CIDR notation for a subnet mask of 255.255.255.0 — the first 24 bits of the address identify the network, and the remaining 8 bits identify hosts within it, giving 256 total addresses and 254 usable host addresses. See the full guide for the binary math behind this.

How many usable hosts are in a /24, /28, or /30 subnet?

A /24 has 254 usable hosts, a /28 has 14, and a /30 has 2 — calculated as 2 to the power of the remaining host bits, minus 2 for the network and broadcast addresses. /31 and /32 are special cases used for point-to-point links and single hosts.

How do I split a network into smaller subnets?

Use the subnet splitter checkbox above — enter how many equal subnets you need, and it lists each resulting network with its own address range, calculated from your base network and CIDR.

Does this calculator send my network details anywhere?

No. Everything runs in the browser with plain JavaScript — nothing typed into this page is transmitted to any server. See the privacy policy for details.