IPv4 Subnet Calculator
Interpret an IPv4 address and CIDR prefix to derive network, broadcast, mask and address-range information.
How to use this calculator
- Enter a valid dotted-decimal IPv4 address and an integer CIDR prefix from 0 through 32.
- Check the labels and units before using a result outside this page.
- Change one input at a time if you want to compare scenarios.
Formula and method
Network = address AND subnet mask; broadcast = network OR inverse mask
- Network = address AND subnet mask; broadcast = network OR inverse mask
- /31 is commonly used for point-to-point links and /32 represents one address; routing and allocation policies are context-dependent.
Worked examples
Worked example
192.168.1.23/24 produces network 192.168.1.0 and broadcast 192.168.1.255.
A /24 contains 256 total IPv4 addresses and commonly 254 host addresses under traditional subnet conventions.
A /24 contains 256 total IPv4 addresses and commonly 254 host addresses under traditional subnet conventions.
Understanding the result
Interpret an IPv4 address and CIDR prefix to derive network, broadcast, mask and address-range information.
/31 is commonly used for point-to-point links and /32 represents one address; routing and allocation policies are context-dependent.
Important notes
/31 is commonly used for point-to-point links and /32 represents one address; routing and allocation policies are context-dependent.
Displayed outputs are rounded for readability; preserve full precision when continuing a calculation.
Frequently asked questions
What does this ipv4 subnet calculator calculator show?
Interpret an IPv4 address and CIDR prefix to derive network, broadcast, mask and address-range information.
Which inputs should I check first?
Enter a valid dotted-decimal IPv4 address and an integer CIDR prefix from 0 through 32.
Can the result be used as a final professional specification?
/31 is commonly used for point-to-point links and /32 represents one address; routing and allocation policies are context-dependent.
Related calculators
- Image Pixel Density Calculator — Estimate pixels per inch from image dimensions and a physical diagonal measurement.
- Electricity Cost Calculator — Estimate electricity use in kilowatt-hours and energy cost from appliance wattage, usage time, and tariff.
- Speed Distance Time Calculator — Calculate speed from distance and elapsed time.
- Data Compression Ratio Calculator — Compare original and compressed data sizes to calculate a compression ratio and percentage of space saved.
- Download Time Calculator — Estimate ideal file download time from file size and connection speed using decimal megabytes and megabits per second.
- Fuel Efficiency Calculator — Calculate fuel consumption in litres per 100 kilometres, kilometres per litre, and optional trip fuel cost.
Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
- How to Calculate a Z-Score — Learn how a z-score shows how far a value is from the mean in standard-deviation units.
- How to Calculate Salary from an Hourly Rate — Convert hourly pay into weekly, monthly, and annual estimates and understand the assumptions behind the result.
- Percent Difference — Understand percent difference, when it is appropriate, and how it differs from percentage change and percent error.
This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.