Frequently Asked Questions

General questions about CalcLoop itself. Looking for a question about a specific calculator? Each tool has its own FAQ section on its page.

Is CalcLoop really free, with no sign-up?

Yes. Every calculator is free, requires no account, and has no usage limit. CalcLoop is supported by ads and voluntary donations — see the donate page.

Does anything I type get sent to CalcLoop's servers?

No. Every calculator runs entirely in your browser using JavaScript. The handful of tools that query external data (DNS Lookup, SPF/DMARC checkers, the blacklist checker) send that query directly from your browser to a public DNS resolver — it never passes through or is logged by CalcLoop's own servers. See the privacy policy for details.

How accurate are the calculators, and what are they based on?

Each calculator is built against the relevant official standard, RFC, or vendor documentation (RFC 7208 for SPF, RFC 7489 for DMARC, official MikroTik RouterOS docs, and so on). The full list of sources per tool is on the methodology page. Where a tool makes a simplifying assumption, that's noted directly on its own page.

What's the difference between a "static formula" tool and a "live check" tool?

Static tools (RAID, Subnet, SLA, Bandwidth, DNS TTL, Backup Retention, MikroTik, Cron, SPF/DMARC generators) compute results from a fixed formula or standard — nothing is fetched from the internet. Live check tools (DNS Lookup, SPF Checker, DMARC Checker, Blacklist Checker) query a public resolver in real time, so results reflect the current state of the domain or IP you enter, not a cached answer.

Can I request a new calculator?

Yes — get in touch via the contact page with what you'd find useful. Requests that come up repeatedly are the ones most likely to get built.

How often is the content reviewed?

Each calculator page shows a "Reviewed" date or a "Live check" label near the results, so you can see at a glance whether you're looking at a periodically-reviewed formula or a real-time query. See the methodology page for the full breakdown.

I found an error or an outdated reference — how do I report it?

Please use the contact page. Corrections to formulas, standards references, or broken tools are prioritized over new feature requests.