IP Address Lookup & Subnet Calculator
Find your public IP address with geolocation details, look up any IP address, and calculate subnets with CIDR notation, network ranges, and host counts.
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Subnet Calculator
Common Subnet Reference
| CIDR | Subnet Mask | Addresses | Usable Hosts | Use Case |
|---|---|---|---|---|
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 | Class A networks |
| /16 | 255.255.0.0 | 65,536 | 65,534 | Class B networks, large orgs |
| /20 | 255.255.240.0 | 4,096 | 4,094 | Cloud VPC subnets |
| /24 | 255.255.255.0 | 256 | 254 | Standard LAN subnet |
| /25 | 255.255.255.128 | 128 | 126 | Half a /24 subnet |
| /26 | 255.255.255.192 | 64 | 62 | Small office network |
| /27 | 255.255.255.224 | 32 | 30 | Small subnet |
| /28 | 255.255.255.240 | 16 | 14 | Point-to-point + devices |
| /29 | 255.255.255.248 | 8 | 6 | Small server cluster |
| /30 | 255.255.255.252 | 4 | 2 | Point-to-point link |
| /32 | 255.255.255.255 | 1 | 1 | Single host route |
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Frequently Asked Questions
What is my IP address?
Your IP (Internet Protocol) address is a unique number assigned to your device by your Internet Service Provider (ISP). It identifies your device on the internet and is used for routing traffic. Your public IP is shown at the top of this page — it's the address that websites and services see when you connect to them.
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation expresses an IP address and its subnet mask as a single value, like 192.168.1.0/24. The number after the slash indicates how many bits of the address are the network prefix. A /24 means 24 bits for the network (256 total addresses, 254 usable hosts), while a /16 means 16 bits (65,536 addresses).
What's the difference between public and private IP addresses?
Private IP addresses (10.x.x.x, 172.16-31.x.x, 192.168.x.x) are used within local networks and can't be reached directly from the internet. Public IP addresses are globally unique and routable on the internet. Your router has a public IP; devices behind it use private IPs. NAT (Network Address Translation) bridges the two.
Is this lookup data accurate?
IP geolocation data is sourced from ipinfo.io and is generally accurate to the city level for most ISPs. However, VPN, proxy, or corporate network users may see the location of their exit node rather than their physical location. The subnet calculator uses pure math and is always exact.