Subnet Calculator

Calculate IPv4 subnets, network ranges, broadcast addresses, wildcard masks, and hosts counts.

Subnet Calculator Options
Result Details
Enter parameters and click Calculate to view.
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Developer Tool

Subnet Calculator

Deconstruct IPv4 CIDR blocks and IP ranges.

100% Free & Local
STEP 01

Input IP Address

Type the base IPv4 address (e.g. 192.168.1.100) you wish to configure.

STEP 02

Select Subnet Mask

Choose your CIDR subnet identifier block (e.g. /24 representing 255.255.255.0).

STEP 03

Bitwise Staging

The calculator performs binary logical AND configurations to identify host address thresholds.

STEP 04

Inspect Networks

Inspect network IDs, gateway IP thresholds, broadcast bounds, and hosts capacity details.

Your Privacy Matters

All calculations run locally in your browser.

No Server Uploads

No variables or results are sent to our servers.

Auto-Cleared

Your session data is erased upon closing the tab.

Capabilities

Key Capabilities

Complete Features

IP Bitwise Processor

Translates standard decimal IPs into 32-bit binary configurations for subnet logic.

CIDR Subnet Selectors

Processes values from Class A, B, and C standard domains (CIDR /8 to /32).

Usable Host Counters

Calculates usable device addresses per subnet (2^(32-N) - 2) automatically.

Wildcard Mask Solves

Computes the wildcard reverse mask values useful for Cisco ACL configurations.

Local Sandbox Execution

No network settings are logged. Your IP allocation logic remains completely offline.

Help

Common Questions Answered

Support
Q1 What is CIDR notation?
Classless Inter-Domain Routing (CIDR) represents the subnet mask by indicating the number of routing prefix bits (e.g., /24 means 24 bits are set to 1, equivalent to 255.255.255.0).
Q2 Why are the first and last IP addresses in a subnet unusable?
The first IP is the network address (which identifies the subnet itself), and the last IP is the broadcast address (used to send messages to all devices in the subnet).
Q3 What is the purpose of subnetting?
Subnetting divides a large network into smaller, manageable, and secure logical sections, reducing broadcast traffic and improving network routing efficiency.
Q4 How does a /31 subnet work?
A /31 subnet contains only two IP addresses, defined under RFC 3021 for point-to-point physical link connections where network and broadcast addresses are omitted.
Q5 What is a loopback address?
Loopback addresses (e.g. 127.0.0.1) are reserved IP scopes used by the device to establish connection parameters with itself, outside of subnets.