Subnet Calculator App for iPhone

Calculate CIDR ranges, IP subnets, host counts, and network boundaries instantly -- the subnet reference tool that fits in your pocket.

Download Free on the App Store

Subnet Calculator and all 19 tools are free. No ads, no account required.

What PingKit's Subnet Calculator Does

Enter any IP address with a CIDR prefix or subnet mask and PingKit instantly calculates the full subnet details. No mental math, no binary conversion tables, no flipping between calculator apps. It handles the subnetting so you can focus on the actual network design.

CIDR Conversion

Enter a CIDR prefix like /22 and see the equivalent subnet mask (255.255.252.0), or enter a dotted decimal mask and get the CIDR notation. Both directions, instantly.

IP Range Display

See the exact first and last usable IP address in any subnet. Know at a glance that 10.0.1.0/24 runs from 10.0.1.1 through 10.0.1.254 without counting in your head.

Host Count

Get the total number of addresses and usable hosts for any prefix length. A /20 gives you 4,094 usable hosts -- PingKit does the 2^n - 2 calculation for you.

Subnet Details

Network address, broadcast address, wildcard mask, and address class are all displayed together. Everything you need for firewall rules, ACLs, and routing tables in one view.

When You Need a Subnet Calculator

Network Planning

Designing a new office network or segmenting a data center VLAN? The subnet calculator tells you exactly how many hosts each prefix supports so you can allocate ranges without waste. Plan a /25 for the engineering floor (126 hosts), a /27 for the conference rooms (30 hosts), and a /28 for management (14 hosts) -- all verified on the spot.

IP Addressing

When you're assigning static IPs or configuring DHCP scopes, you need to know the valid range. Enter the subnet and immediately see which addresses are usable. No more accidentally assigning the network or broadcast address and wondering why the device can't communicate.

CIDR Notation Reference

Not everyone has the CIDR table memorized. When a firewall rule says 10.0.0.0/12 and you need to know exactly what that covers, PingKit converts it instantly. Especially useful when reviewing security group rules or cloud VPC configurations on the go.

Subnetting for Exams

Studying for CCNA, CompTIA Network+, or AWS certifications? Use PingKit to verify your subnetting homework. Work the problem by hand first, then check your answer with the calculator. It's faster than looking up a reference chart and you can practice anywhere.

Part of a Complete Toolkit

Subnetting doesn't happen in isolation. Once you've planned your addressing scheme, use PingKit's other tools to verify it works -- ping devices to confirm reachability, run a network scan to discover what's actually on each subnet, check DNS resolution, or trace the route between segments. Having the calculator and the diagnostic tools in the same app means fewer context switches during network configuration.

Calculate any subnet.

Download PingKit free and get instant CIDR and subnet calculations.

Download Free on the App Store

Requires iOS 17.0 or later.