Interactive tools
Tools for a clearer head
Small, honest calculators and checkers built on the same primary research as our articles. They run entirely in your browser, save nothing, and are educational estimates, not a diagnosis. When a tool points to something medical — iron, B12, thyroid — it tells you to go get the bloodwork.
- Symptom checkerBrain-Fog Cause FinderToggle the symptoms and context that fit you — poor sleep, low-iron risk, thyroid signs, B12/vegan diet, new medications, dehydration, post-meal slumps, perimenopause, high stress — and see the likely contributors behind your fog, each with a short evidence note and a clear prompt to get bloodwork when it matters.Find likely causes
- Caffeine & sleepCaffeine Cutoff CalculatorEstimate how much caffeine from a coffee, espresso, energy drink, or tea is still circulating at bedtime — and the last safe time to have it so residual caffeine stays under the common sleep-disruption threshold. Late caffeine is a quiet driver of next-day fog.Find your cutoff
Start with the reading
The tools are a way in; the depth is in the articles. These are the best places to begin.
- What causes brain fogThe full map of common contributors, evidence-graded.
- How to clear brain fogWhat actually moves the needle, in order of impact.
- The afternoon crashWhy a second coffee backfires — pairs with the cutoff tool.
- Best cognitive-energy picks (2026)Our evidence-graded hub for energy and focus.
These tools are informational and not medical advice. They cannot diagnose a condition, account for your full history, or replace testing and a clinician's judgment. Persistent or worsening brain fog — especially with weight change, low mood, numbness, heavy periods, or a new medication — deserves a real evaluation. Talk to a licensed clinician.