IPv4 Subnet Calculator
Calculate network address, broadcast address, host range and usable hosts for an IPv4 CIDR block.
What is IPv4 Subnet Calculator?
Calculate network address, broadcast address, host range and usable hosts for an IPv4 CIDR block. This tool runs directly in a modern browser and is designed for fast everyday calculations without signup.
How to use this tool
- Enter the values you already know.
- Choose the relevant options or units.
- Select the action button to calculate or convert the result.
IPv4 subnet basics
A CIDR prefix such as /24 determines how many leading address bits belong to the network. This calculator derives the subnet mask, network address, broadcast address and conventional usable-host range.
Practical example
Try the tool with a realistic set of values from your own task, then change one input at a time. Comparing two scenarios is often the easiest way to understand the result and spot data-entry mistakes.
Important notes
Results are provided as a practical calculation or conversion aid. For financial, engineering, tax, legal or operational decisions, confirm any provider-specific rules, official rates, rounding conventions or regulatory requirements before relying on the result.
Why use this tool?
- Free to use without creating an account.
- Fast results in desktop and mobile browsers.
- Clear inputs with no unnecessary steps.
- Related tools are linked below for follow-up calculations.
CIDR defines the network prefix
An IPv4 CIDR such as /24 means that 24 bits are used for the network prefix. The remaining bits define addresses inside that subnet. Traditional IPv4 subnets reserve the network and broadcast addresses, leaving a smaller range for ordinary host assignments.
Usable-host conventions can vary
Point-to-point links and modern networking practices can use special prefix rules, so the classic usable-host formula is not universal for every prefix length. Confirm the behavior expected by your router, cloud provider or network design.
Frequently Asked Questions
Is IPv4 Subnet Calculator free to use?
Yes. You can use the tool without creating an account or paying a fee.
Does this tool work on mobile devices?
Yes. The interface is designed for modern mobile and desktop browsers.
Can I use the result as an official figure?
Use it as a practical estimate or conversion. Confirm important financial, engineering, legal or provider-specific figures with the relevant official source.
How many addresses are in a /24 IPv4 subnet?
A /24 contains 256 total IPv4 addresses. In a traditional subnet, 254 are commonly treated as usable host addresses after reserving network and broadcast addresses.
What does /32 mean?
A /32 identifies a single IPv4 address with no host bits remaining.