Subnetting: Subnet Calculator

Master IP subnetting with short practice rounds and a subnet calculator. Find the network address, broadcast address, subnet mask, first and last host and number of hosts for any IPv4 address, and see the step-by-step working after every answer.

Made for networking students and IT pros doing exam prep for networking certifications, job interviews, or anyone who wants subnetting to finally click.

HOW IT WORKS • You get an IP address with a CIDR prefix, like 192.168.1.77/26 • Answer one question: network, broadcast, mask, first host, last host or usable hosts • See instantly if you are right, with the full block-size working • Practice a few minutes a day and grow your streak

INCLUDED AT NO COST • Subnetting practice quiz for /24 to /30 networks • Subnet calculator for any IPv4 address and prefix from /0 to /32: subnet mask, network, broadcast, host range and host count, plus how it is calculated • "How subnetting works" lesson: the block-size method explained with one worked example • A step-by-step explanation after every answer

FULL VERSION (one-time purchase, no subscription) • Subnetting practice for every prefix from /8 to /30, the full exam range • Exam mode: 10 timed questions with no hints. Beat your best score and time • Mistake review: every wrong answer is saved, so you can practice it until you get it right

WHY SUBNETTING PRACTICE • Learn the fast block-size method used in subnetting exams, not just a calculator • Works fully offline • No ads, no account, no data collected • Simple design that follows your phone's light or dark theme

Whether you need a quick subnet mask calculator, an IP subnetting quiz or CIDR practice before your exam, Subnetting Practice helps you get fast and accurate.

Recent changes:
Smaller and faster: this update optimizes the app's code and trims the download size, so it installs quicker and runs smoother. No feature changes — your saved progress, best exam result, and purchases carry over as usual.