NetworkCalc API

Base URL

https://networkcalc.com/api

Authentication

No key or account. The API mirrors the free web tools on the same domain.

Rate limit

Not published. Results are fully deterministic, so cache them and you will never need many requests.

Pricing

Free.

CORS

Enabled — callable directly from browser JavaScript

Official docs

Read the docs

Every request below was executed against the live API on 2026-08-21, and the response shown is the real body it returned — not an illustration.

curl 'https://networkcalc.com/api/ip/10.0.0.1/24'

const res = await fetch("https://networkcalc.com/api/ip/10.0.0.1/24");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);

import requests

res = requests.get("https://networkcalc.com/api/ip/10.0.0.1/24", timeout=20)
res.raise_for_status()
print(res.json())

{
  "status": "OK",
  "meta": {
    "permalink": "https://networkcalc.com/subnet-calculator/10.0.0.1/24",
    "next_address": "https://networkcalc.com/api/ip/10.0.0.2/24"
  },
  "address": {
    "cidr_notation": "10.0.0.1/24",
    "subnet_bits": 24,
    "subnet_mask": "255.255.255.0",
    "wildcard_mask": "0.0.0.255",
    "network_address": "10.0.0.0",
    "broadcast_address": "10.0.0.255",
    "assignable_hosts": 254,
    "first_assignable_host": "10.0.0.1",
    "last_assignable_host": "10.0.0.254"
  }
}

statusstring

`OK` on success. Check this before reading `address`, because errors still return HTTP 200 in some cases.

address.cidr_notationstring

The input echoed back in canonical form, useful for confirming the API parsed what you meant.

address.subnet_mask / wildcard_maskstring

Dotted-quad mask and its inverse. The wildcard mask is what you need for ACLs on Cisco-style equipment.

address.network_address / broadcast_addressstring

First and last address of the block, neither of which is assignable to a host.

address.assignable_hostsinteger

Usable host count, already excluding network and broadcast. A /24 returns 254.

address.first_assignable_host / last_assignable_hoststring

Bounds of the usable range, ready to paste into a DHCP pool definition.

meta.next_addressstring

A prepared API URL for the next address in the block, so you can walk a range without building URLs yourself.

• Validate a subnet plan in a provisioning script before creating cloud networks
• Generate DHCP pool boundaries automatically from a CIDR block
• Add a subnet calculator to an internal admin tool without writing bit maths
• Resolve DNS records from a script without depending on the local resolver
• Teach subnetting with a live endpoint students can query from any language