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Calculators that explain their result.
Built by the engineers of a German data center operator for the questions that come up in real operations: how many Microsoft licenses an environment needs, which subnet fits eighty IP phones, and how long a RAID 5 with large disks runs without protection. Every number shows the rule or assumption behind it.
Microsoft licensing calculator
Windows Server core licenses, User/Device CALs, RDS CALs, SQL Server and Exchange – quantities for purchase and for SPLA rental.
Calculates the rules, not the prices: every line names the rule behind it, and the core grid shows the cores the minimums make you pay for.
Open →Subnet calculator
Network address, mask, usable range and broadcast – plus the reverse question: which prefix fits a given number of devices.
The 32 bits are drawn as a band and the mask visibly cuts them. Once you have seen that a /26 leaves six host bits, you never need the formula again.
Open →What is my IP address?
Your public IPv4 and IPv6 address, shown separately, plus the reverse DNS name registered for it.
Explains what the reverse name suggests about a business line and what your device sends with every request – without storing anything.
Open →Speed test
Latency, download and upload – seven seconds in each direction.
Fixed time window instead of a fixed data amount, so every line is measured over the same seven seconds. Test server in Germany, stated openly.
Open →RAID calculator
Usable capacity for RAID 0, 1, 5, 6 and 10 – and the TB-versus-TiB gap the operating system shows.
Adds the two numbers other calculators leave out: how long the array runs unprotected after a disk swap, and the probability that the rebuild itself fails on a read error.
Open →Five more tools – ping test, DNS checker, SPF/DMARC test, password generator, downtime cost – are available in German on the German tools page. English versions follow where the findings can be translated without losing precision.
Why a German data center publishes English tools
We run servers for companies in Germany and host them in ISO 27001 certified data centers here. The tools exist because our engineers needed them; publishing them in English costs little and answers the same questions for people elsewhere. If your company needs servers or a terminal server hosted in Germany – for data residency, for a German subsidiary, for customers who ask where the data lives – the server hosting pages describe what we offer.
Everything here is free and runs in your browser; the calculators send nothing anywhere. Sources are listed on each page with the date we last checked them, because licensing rules and standards change and a tool that silently goes stale is worse than none.