Technical calculator
CIDR and Subnet Calculator
Calculate an IPv4 network address, subnet mask, broadcast address, address count, and usable host range from an IP and CIDR prefix.
Calculated result
$0.00 monthly
$0.00 annually
Methodology and assumptions
Formula: Addresses = 2^(32 − prefix). The subnet mask keeps the prefix bits; the network is IP AND mask, and broadcast is network OR the inverted mask.
Worked example:192.168.1.42/24 resolves to network 192.168.1.0, mask 255.255.255.0, broadcast 192.168.1.255, and 256 total addresses.
Common mistake or edge case:Do not subtract two usable addresses for /31 point-to-point networks: RFC 3021 permits both addresses. A /32 identifies one host route.
Read the supporting guide and worked examples.
Pricing last verified:
Frequently Asked Questions
What does the CIDR and Subnet Calculator calculate?
Calculate an IPv4 network address, subnet mask, broadcast address, address count, and usable host range from an IP and CIDR prefix.
How accurate is the CIDR and Subnet Calculator?
It is a planning estimate based on the inputs, formula, assumptions, and sources shown on this page. Actual prices, invoices, taxes, discounts, and outcomes can differ.
Which pricing source does the CIDR and Subnet Calculator use?
The calculator links to RFC 4632 CIDR specification as its official source. The displayed pricing or reference data was last verified on 2026-09-14.
Are calculator inputs saved or sent to analytics?
Inputs are processed in your browser. Calculator values are not included in analytics events.