Network & DNS🔒 Browser (client-side)API available📴 Works offlineintermediate

CIDR Subnet Calculator

Calculates IPv4 CIDR subnet parameters: network address, broadcast address, netmask, wildcard mask, and usable IP range.

Data stays in your browser

Ready to runInstant execution

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Result

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What does this tool do?

Calculates IPv4 CIDR subnet parameters: network address, broadcast address, netmask, wildcard mask, and usable IP range.

Why would I use it?

You are configuring VPC subnets in AWS, GCP, Azure, or Kubernetes clusters.
You need to know the exact number of usable IP addresses in a CIDR block.
You are auditing firewall allowlists and routing tables.

Real-life example

Input

192.168.1.0/24

Output

Netmask: 255.255.255.0 · Usable Range: 192.168.1.1 - 192.168.1.254 · Usable Hosts: 254

/24 provides 256 total addresses, with 2 reserved for network and broadcast.

Input → Process → Output → Next

Input: Enter IPv4 address with prefix length (e.g. 10.0.0.0/16).
Process: Performs bitwise binary subnet math and calculates host bounds.
Output: Comprehensive network breakdown including first/last usable IP and wildcard mask.
Next action: Apply the CIDR block in your cloud VPC or firewall policy.

Common mistakes

Forgetting that cloud providers (like AWS) reserve 5 IP addresses in each subnet, not just 2.
Confusing CIDR prefix length (/24) with subnet mask (255.255.255.0).
Allocating subnets that overlap with existing corporate networks.

What the result means

Precise mathematical boundary definition of an IP subnet.

Privacy & security

Your input is processed entirely in your browser and never sent to a YAS server.

API

Endpoint

POST https://yas.sh/api/v1/tools/cidr-calculator

Request Header

Content-Type: application/json

cURL

curl -X POST "https://yas.sh/api/v1/tools/cidr-calculator" \
  -H "Content-Type: application/json" \
  -d '{"input":"192.168.1.0/24"}'

JavaScript

const res = await fetch("https://yas.sh/api/v1/tools/cidr-calculator", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
  "input": "192.168.1.0/24"
}),
});
const data = await res.json();

Python

import requests

r = requests.post("https://yas.sh/api/v1/tools/cidr-calculator", json={"input":"192.168.1.0/24"})
data = r.json()

Field	Type	Required	Description
input	string	Yes	CIDR string e.g. 192.168.1.0/24

Success response

{ "slug": "cidr-calculator", "networkAddress": "192.168.1.0", "usableHosts": 254 }

Calculate CIDR IP ranges, netmasks, and usable host counts.

Error responses

400 VALIDATION_ERROR — invalid input or unsupported option.
413 PAYLOAD_TOO_LARGE — input exceeds the 64 KB limit.
429 RATE_LIMIT_EXCEEDED — rate limit exceeded (60 req/min).

Limits

Maximum input: 64 KB per request.
Rate limit: 60 requests/min per IP address.
Authenticated accounts benefit from higher tier quotas.