Subnet Calculator API

POST https://api.findutils.com/api/tools/subnet-calculator/execute

Return the full IPv4 subnet breakdown for an address: network and broadcast address, subnet mask, wildcard mask, binary mask, first and last usable host, total and usable host counts, IP class (A-E), and IP type (public, private, loopback, link-local, multicast, reserved). Accepts CIDR notation (192.168.1.0/24), a bare IP (defaults to /24), or an IP plus a dotted subnet mask.

Needs an API key. Running a tool needs an API key. Keys are not for sale yet: ask for early access. About API keys

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Request body

application/json

ip

string required

IPv4 address, with or without a /prefix, e.g. "192.168.1.0/24" or "10.0.0.5". Without a prefix /24 is assumed unless mask is given.
mask

string optional

Optional dotted subnet mask such as "255.255.255.0". When given it overrides the prefix in ip.

Example arguments

Verified

{
  "ip": "192.168.1.0/24"
}

curl -X POST https://api.findutils.com/api/tools/subnet-calculator/execute \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "ip": "192.168.1.0/24"
  }'

const response = await fetch('https://api.findutils.com/api/tools/subnet-calculator/execute', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json', Authorization: 'Bearer YOUR_API_KEY' },
  body: JSON.stringify({"ip":"192.168.1.0/24"}),
});
const data = await response.json();

import requests

response = requests.post(
    "https://api.findutils.com/api/tools/subnet-calculator/execute",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={"ip":"192.168.1.0/24"},
)
data = response.json()

$ch = curl_init('https://api.findutils.com/api/tools/subnet-calculator/execute');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ['Content-Type: application/json', 'Authorization: Bearer YOUR_API_KEY'],
    CURLOPT_POSTFIELDS => '{"ip":"192.168.1.0/24"}',
    CURLOPT_RETURNTRANSFER => true,
]);
$data = json_decode(curl_exec($ch), true);

Also an MCP tool

Call subnet_calculator from Claude, Cursor or any MCP client. Same arguments, same output.

https://mcp.findutils.com

MCP reference

Rate limit: 60 a minute, per IP
Auth: API key
REST id: subnet-calculator
MCP name: subnet_calculator
Category: Network
Machine-readable: openapi.json · markdown.md

Request body

Example arguments

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