🖧 Gateway IP Address Calculator
Calculate gateway, network, broadcast, and host range from any IP and subnet mask
| CIDR | Subnet Mask | Total IPs | Usable Hosts | Typical Use |
|---|---|---|---|---|
| /30 | 255.255.255.252 | 4 | 2 | Point-to-point link |
| /29 | 255.255.255.248 | 8 | 6 | Small VLAN / DMZ |
| /28 | 255.255.255.240 | 16 | 14 | Small office segment |
| /27 | 255.255.255.224 | 32 | 30 | Small department |
| /26 | 255.255.255.192 | 64 | 62 | Medium VLAN |
| /25 | 255.255.255.128 | 128 | 126 | Half class C |
| /24 | 255.255.255.0 | 256 | 254 | Standard LAN |
| /23 | 255.255.254.0 | 512 | 510 | Large VLAN |
| /22 | 255.255.252.0 | 1024 | 1022 | Campus segment |
| /16 | 255.255.0.0 | 65536 | 65534 | Class B / large site |
| Scenario | Network | Gateway | Usable Hosts |
|---|---|---|---|
| Home Network | 192.168.1.0/24 | 192.168.1.1 | 254 |
| Home Network Alt | 192.168.0.0/24 | 192.168.0.1 | 254 |
| Proxmox Lab | 10.0.0.0/24 | 10.0.0.1 | 254 |
| Server VLAN | 10.10.10.0/24 | 10.10.10.1 | 254 |
| IoT Isolation | 192.168.10.0/26 | 192.168.10.1 | 62 |
| WAN Link | 203.0.113.0/30 | 203.0.113.1 | 2 |
| Management VLAN | 10.1.1.0/28 | 10.1.1.1 | 14 |
The default gateway is the bridge between your local net and the internet Usually it is the router, so devices can talk with the world outside. The IP address of the router is the default gateway address. Knowing it is useful during network crashes or when you must make network changes.
To log in to the admin page of the router, you need the default gateway IPv4 or IPv6 address.
What is a Default Gateway?
Most routers already come with a network that starts at 192.168.0.1 or 192.168.1.1. This is usually the first private IP address in the net, so it is the address of the router. An address like 192.168.1.1 works only inside one net, where traffci travels through the local area net.
Other popular variant is 10.0.1.1.
The default gateway always stays in the same subnet as the IP of your device. Really, it can be any unique address in that subnet, but many network admins choose the first number of the subnet as gateway. Any IP address of the router works in the given subnet.
Using the first or last is simply a custom. In offices usually the netmask is 255.255.255.0, and the gateway has the first or last usable host address, so.1 or.254.
Imagine it like this: An IP address is like the address of some home. The gateway is the local post office. When a device wants to reach something away from the subnet, usually the internet, it must pass through the gateway.
When a device does not know where to send packets, it sends them to the default gateway. For a host it is the nearest router. The gateway works in the third layer of the OSI model, the network layer.
It has a physical and logical address. It is the interface of the router, connected to the local net, that sends packets out.
If a computer with IP 192.168.8.2 wants to reach 192.168.7.4, it must pass the data through its gateway, which then forwards them to the right net and host. Every router along the way checks if the destination IP matches some known net.
To find the default gateway in Windows, open the Command Prompt, type ipconfig and press Enter. Scroll up, and you will find “Default gateway” with the IP address listed. It is the internal or LAN address of the router.
Devices need it to send data to the internet. Local communication passes through the gateway, where the router or next tool changes it to a public address using NAT. The device only cares about its gateway; the router does the rest.
Every host needs a default gateway so that DHCP can work. Otherwise you would spend days assigning settings by hand. If you assign the gateway IP address to a non-router device, you lose connection to everything outside the net.
