Developer & Networking
IPv4 Subnet Calculator
Divide an IPv4 network into multiple subnets by specifying the desired number of subnets or hosts per subnet, with a full breakdown table.
FREE INSTANT RESULTS NO SIGNUP UPDATED 2026
Parameters
Summary Output
New Subnet Mask
/26 (255.255.255.192)
Max Subnets Created
4
Usable Hosts per Subnet
62
Visual Breakdown
Schedule Breakdown
How to Use
Enter the base network IP and its current CIDR prefix. Choose whether you want to divide by number of subnets or by hosts per subnet, then enter the desired count. The calculator determines the required new subnet mask and generates a detailed breakdown table.
Example Calculation
Dividing 192.168.1.0/24 into 4 subnets: New mask = /26 (255.255.255.192), each subnet has 62 usable hosts. Subnets: .0/26, .64/26, .128/26, .192/26.
Formula
By Subnet Count:\n New prefix = Base prefix + ceil(log₂(desired subnets))\n\nBy Host Count:\n Host bits = ceil(log₂(desired hosts + 2))\n New prefix = 32 − Host bits\n\nUsable Hosts per Subnet = 2^(32 − new prefix) − 2\nMax Subnets = 2^(new prefix − base prefix)
Frequently Asked Questions
Common questions and answers about the IPv4 Subnet Calculator.
The IPv4 Subnet Calculator is a free online tool designed to divide an ipv4 network into multiple subnets by specifying the desired number of subnets or hosts per subnet, with a full breakdown table. It allows you to perform these calculations quickly and accurately without manual computations.
Enter the base network IP and its current CIDR prefix. Choose whether you want to divide by number of subnets or by hosts per subnet, then enter the desired count. The calculator determines the required new subnet mask and generates a detailed breakdown table. Once you enter these values, the calculator will automatically compute and display the results instantly.
The IPv4 Subnet Calculator uses the following formula to calculate your results:
By Subnet Count:\n New prefix = Base prefix + ceil(log₂(desired subnets))\n\nBy Host Count:\n Host bits = ceil(log₂(desired hosts + 2))\n New prefix = 32 − Host bits\n\nUsable Hosts per Subnet = 2^(32 − new prefix) − 2\nMax Subnets = 2^(new prefix − base prefix)
This formula is standard and widely accepted for these types of calculations.
Sure! Here is a practical example:
Dividing 192.168.1.0/24 into 4 subnets: New mask = /26 (255.255.255.192), each subnet has 62 usable hosts. Subnets: .0/26, .64/26, .128/26, .192/26.
This example demonstrates how the inputs are processed through the formula to yield the final results.
To use the IPv4 Subnet Calculator, you need to enter: Base Network IP, Base Subnet Mask, Subnetting Criteria, Count / Limit. These inputs help the tool calculate precise results tailored to your situation.
The IPv4 Subnet Calculator outputs the following details: New Subnet Mask, Max Subnets Created, Usable Hosts per Subnet. This comprehensive breakdown helps you understand the different aspects of the calculated figures.
Yes, the IPv4 Subnet Calculator is 100% free with no registration or signup required. It is fully responsive and optimized for mobile phones, tablets, and desktop computers.
Reliable Calculator provides a fast, clean, ad-free, and premium user experience. The IPv4 Subnet Calculator uses verified math formulas and provides instant results with visual breakdowns and examples, making it more intuitive than other tools.
Categories
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