Tools
Each of these came out of a guide where the answer turned out to be a decision procedure rather than a paragraph. They run entirely in your browser, they send nothing anywhere, and the rules each one works from are printed on its page so you can check the answer rather than trust it.
Where a service publishes no figure, the tool says so instead of estimating one. That is the least satisfying thing a calculator can do and it is better than a confident number nobody stands behind.
Atmos Signal Path Checker
Walk your own signal chain and get the specific link that is stopping Atmos, not a checklist of everything it might be.
Download Expiry Planner
Enter your trip and see when to download, and why testing a download by playing it is the thing that breaks it.
Netflix Top 10 Re-Ranker
Hold hours viewed constant, stretch the runtimes, and watch views fall and ranks slide. The denominator, made adjustable.