Tools
Calculators I use while planning homelab and infrastructure work. Each one runs entirely in your browser: nothing is uploaded, there is no sign-up, and every figure is plain arithmetic on the numbers you enter.
RAID Capacity Calculator
NAS and storageUsable capacity, space lost to parity and how many drives can fail, for RAID 0, 1, 5, 6, 10, SHR-1 and SHR-2. Handles mixed drive sizes.
IPv4 and IPv6 Subnet Calculator
NetworkingNetwork address, broadcast or last address, netmask and usable host count for any IPv4 or IPv6 CIDR, including how an IPv4 network splits into /24s, /26s and /28s.
Network Transfer Time Calculator
NAS and networkingHow long a copy takes over 100 Mbit to 25 Gbit ethernet, at line rate or at the share of throughput you actually expect to see.
VLAN ID Planner
NetworkingValidate VLAN IDs against the 802.1Q range, catch duplicates, and find the free blocks left for the next site or segment.
Why calculators instead of articles
A search for a RAID size or a subnet split is a task, not a research question, and it is the kind of query an AI answer will happily summarise instead of sending you to a page. These tools exist so there is a reason to land on the site: you get the number immediately, and the surrounding article explains why it came out that way.
The articles these link into cover the reasoning. RAID overhead is explained in the NAS buying guide, VLAN design in the MikroTik VLAN filtering walkthrough, and why a fast link still feels slow in the bufferbloat post.