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Subnet Calculator

Calculate IPv4 subnet details fast, from network and broadcast addresses to host ranges, masks, wildcard masks, and VLSM subnet layouts.

/

Leave the prefix blank to derive it from the mask automatically.

Network Address

192.168.1.0

Broadcast Address

192.168.1.255

First Usable Host

192.168.1.1

Last Usable Host

192.168.1.254

Usable Hosts

254

Subnet Mask

255.255.255.0

Wildcard Mask

0.0.0.255

IP Class

Class C

CIDR

/24

Binary Representation

11000000 . 10101000 . 00000001 . 00011001

Common CIDR Reference

Quick lookup table for IPv4 subnet masks and usable host counts.

CIDRSubnet MaskUsable Hosts
/8255.0.0.016,777,214
/9255.128.0.08,388,606
/10255.192.0.04,194,302
/11255.224.0.02,097,150
/12255.240.0.01,048,574
/13255.248.0.0524,286
/14255.252.0.0262,142
/15255.254.0.0131,070
/16255.255.0.065,534
/17255.255.128.032,766
/18255.255.192.016,382
/19255.255.224.08,190
/20255.255.240.04,094
/21255.255.248.02,046
/22255.255.252.01,022
/23255.255.254.0510
/24255.255.255.0254
/25255.255.255.128126
/26255.255.255.19262
/27255.255.255.22430
/28255.255.255.24014
/29255.255.255.2486
/30255.255.255.2522
/31255.255.255.2542
/32255.255.255.2551
Editorial noteMaintained by EveryCalc - Reviewed June 2026

EveryCalc calculators are designed for fast, practical estimates with transparent inputs and no required account. We use plain formulas, visible assumptions, and related tools so visitors can check the result from more than one angle.

Results are informational only. For financial, tax, legal, medical, construction, or other high-impact decisions, verify the output against primary sources or a qualified professional.

Learn more about our review process on the EveryCalc methodology page.

How this calculator works

What this page estimates

This Subnet Calculator is built to give a quick, browser-based estimate for subnet. Calculate IPv4 subnet details fast, from network and broadcast addresses to host ranges, masks, wildcard masks, and VLSM subnet layouts. The inputs stay on the page during normal use, and the result should be treated as an estimate for planning, comparison, or education rather than professional advice.

Calculation approach

The calculator applies the standard relationship implied by the inputs, then formats the answer so it can be checked and reused. For tech & developer tools, the most important step is using consistent units, rates, time periods, and assumptions before comparing the result with another calculator or outside quote.

Example workflow

For example, start with a realistic value you already know, change one input at a time, and watch how the answer moves. That makes it easier to tell whether the result is being driven by the main amount, the rate, the time period, or a unit conversion.

Practical checks

  • Use current, real-world numbers when the result affects money, health, tax, or legal decisions.
  • Run a low, base, and high case when the inputs are estimates.
  • Check the related calculators below when the next decision depends on a different assumption.

How to interpret the subnet result

Best use

Use the result to check a technical assumption, format data, estimate usage, or speed up a development workflow without installing a separate tool.

Cross-check

Compare the output with official documentation, production logs, billing dashboards, test fixtures, or the exact runtime environment you plan to use.

Watch for

APIs, model pricing, encodings, and platform limits can change. Treat static numbers as a starting point and verify anything tied to production cost or security.

This page belongs to the Tech & Developer calculator library, so the answer should be read in the context of the decision you are modeling rather than as a universal rule.

Before relying on this subnet estimate

Most calculator mistakes come from the inputs, not the arithmetic. Use this short audit before you reuse the answer in a spreadsheet, quote, application, or important conversation.

Verify the runtime

Encoding, limits, pricing, formats, and platform behavior can differ by API version, browser, framework, or deployment environment.

Avoid sensitive data

Do not paste secrets, tokens, customer records, or regulated data into any public browser utility unless you have cleared that workflow.

Test production assumptions

Use the output as a quick check, then confirm security, billing, and performance assumptions in the real system.

Rerun this page when platform documentation, model pricing, payload shape, browser behavior, or production limits change.

How to Use

  1. Enter an IPv4 address and either a CIDR prefix like /24 or a subnet mask like 255.255.255.0.
  2. Review the calculated network address, broadcast address, usable host range, wildcard mask, and binary representation.
  3. Switch to VLSM / Subnet Divider to split a larger network into equal-size subnets or allocate different host counts per subnet.
  4. Use the CIDR reference table to compare common prefixes, masks, and host capacities before designing your network.

Frequently Asked Questions

What does CIDR mean?

CIDR stands for Classless Inter-Domain Routing. It uses a slash notation like /24 to show how many bits belong to the network portion of an IPv4 address, which makes subnetting more flexible than older class-based addressing.

What is the difference between a subnet mask and a wildcard mask?

A subnet mask marks the network bits with 1s and the host bits with 0s. A wildcard mask is the inverse, with network bits as 0s and host bits as 1s. Wildcard masks are often used in routing and ACL configurations.

How many usable hosts are in a subnet?

For most IPv4 subnets, usable hosts equal total addresses minus 2, because one address is the network address and one is the broadcast address. Special cases include /31 point-to-point networks and /32 single-host routes.

What is VLSM?

VLSM stands for Variable Length Subnet Masking. It lets you create subnets of different sizes inside the same parent network, so you can avoid wasting IP space and match each subnet to the number of hosts it actually needs.

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