IPv4 Subnet Calculator

Subnet maths, instantly.

Paste an IP address in CIDR notation or with a subnet mask, and get network address, broadcast, usable host range, wildcard mask, binary breakdown, and subnet splits — all in one place.

Step 01 ⌨️ Enter an IP — CIDR, dotted mask, or bare address

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Step 02 🔢 Get network, broadcast, host range, masks, and binary breakdown

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Step 03 🔀 Optionally split the network into equal subnets with a click

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Flexible input

Accepts CIDR notation (192.168.1.0/24), dotted subnet mask (10.0.0.1 255.255.0.0), or a bare IP address. Host addresses are automatically mapped to their network.

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Full breakdown

Network address, subnet mask, wildcard mask, broadcast address, first and last usable host, usable host count, and total address count — all shown at once.

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Binary view

See address, netmask, wildcard, and network in binary — with network bits highlighted in teal and host bits in grey. Great for understanding CIDR at a glance.

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Subnet splitter

Divide any /1–/29 network into equal-sized subnets up to /30. Choose a target prefix and get a full table of sub-networks, host ranges, and broadcast addresses.

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IP classification

Automatically identifies private (RFC 1918), public, loopback, link-local, multicast, and reserved ranges. Also shows the classical IP class (A / B / C / D / E).

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Shareable URLs

Every calculation updates the URL query string. Bookmark or share the link and it will re-run the same lookup automatically on load.

Free account

3 lookups per week

Create a free account and run up to 3 subnet lookups per week. All features are included — binary view, subnet splitter, shareable URLs. Quota resets every Monday.

Licensed

Unlimited lookups

Contact SS Data to get a license — no weekly quota, full access to all features forever on your account.

Free to use — built in free time.

Net is a personal project developed in free time by SS Data AS. SS Data is not currently an operational company. The free tier is open to anyone with an account. Contact us if you need a full license.