Subnet Calculator: IP & CIDR

A clean, precise IPv4 and IPv6 subnet tool for calculating networks, converting address ranges to minimum CIDR blocks, and splitting networks into equal subnets.

Subnet Calculator is a focused IPv4 and IPv6 toolkit for network engineers, system administrators, developers, and students.

Enter an IP address and prefix to see the network, mask, wildcard mask, broadcast address, usable range, and address capacity. Enter an address range to convert it into the smallest exact set of CIDR blocks. Switch to Split mode to divide a network or an aligned address range into equal-size subnets.

Key features:

• IPv4 and IPv6 address, CIDR, and prefix calculations
• IPv4 dotted-decimal subnet mask input
• Short IPv4 ranges such as 192.168.0.1-100
• IPv4 and IPv6 ranges converted to minimum CIDR blocks
• Equal-size IPv4 and IPv6 subnet splitting
• Correct handling of IPv4 /0, /31, and /32, and IPv6 /0 through /128
• Copy individual results, complete summaries, or full CIDR lists
• Native support for iPhone, Apple silicon Mac, and Intel Mac

All calculations run locally on your device. The app contains no ads, does not track you, and does not upload the IP addresses you enter.

Claim a free 7-day full-feature trial through the App Store. The trial does not renew and never charges automatically. After the trial, make one US$0.99 purchase to unlock the app permanently on iPhone and Mac with the same Apple Account.