Brain
Brain Fog and Memory Problems: When Hormones Affect Your Mind
By WellCal Editorial Team , DN-Usama Awan (Reviewer) May 12, 2026 You walked into the kitchen and forgot why. Mid-sentence,
May 12, 2026
Instant, evidence-based results for BMI, calories, macros, hydration, sleep, fertility, and more — no sign-up, no fees, no inflated promises.
“Our formulas reference published research from these organizations. WellCal is independent — not affiliated or endorsed.” See our methodology
Health metrics shouldn't require a degree to understand. WellCal turns the formulas dietitians, fitness coaches, and clinicians use into clear, instant answers — so instead of wondering whether you're hitting the right protein target, calorie window, or hydration level, you just see the number that fits your body.
Every tool is free. None require an account. All run in your browser, on any device, in under ten seconds.
Pick the metric you want to understand. Each tool delivers a personalized result from the numbers you enter.
Every WellCal tool answers a specific health question. Here's what each one does and how to read your result.
Body Mass Index is the screening number clinicians use worldwide to flag weight-related health risk. Enter height and weight to see your BMI score and category instantly. BMI doesn't measure muscle mass, so athletes and lifters should read the result alongside our FFMI Calculator or Body Age tools for a fuller picture.
Our calorie tool uses the Mifflin-St Jeor equation, widely regarded as the most accurate predictor of resting metabolic rate. Enter age, sex, height, weight, and activity to see your Total Daily Energy Expenditure (TDEE), then adjust based on whether your goal is loss, gain, or maintenance.
Calories alone don't tell the full story. The macro split tool divides your daily target into protein, carbs, and fats using ratios supported by sports nutrition research. New to macros? Read our complete macronutrient guide first.
The Fat-Free Mass Index measures lean tissue relative to height. Researchers use it to estimate genetic muscle potential, and it's one of the most honest benchmarks for tracking long-term strength training progress. Calculate your FFMI →
Protein needs vary widely depending on weight, training load, and goal. Our protein tool gives you a daily target plus a per-meal breakdown, so you can distribute intake across the day to maximize muscle protein synthesis instead of stacking everything into one meal.
The "eight glasses a day" rule was never based on science. Real hydration needs depend on weight, activity level, and climate. Our hydration tool produces a personalized daily target grounded in established dietary reference intakes.
Sleep quality depends on completing full 90-minute cycles, not just total hours in bed. The sleep cycle calculator works backward from your wake time (or forward from bedtime) to suggest sleep windows that end at the lightest stage of sleep — when waking feels easiest.
Most adults eat roughly half the fiber they need. Our fiber calculator gives you a precise daily target based on age and sex, with practical food-source guidance in our high-fiber foods guide
Your biological age can run years younger or older than your chronological age, depending on lifestyle. This tool estimates that gap using sleep, exercise, stress, and diet inputs. Want to lower it? Read our guide to improving body age naturally.
Enter the first day of your last period in the due date calculator to estimate your delivery date and track trimester milestones. Curious why estimates vary? Our article on what affects due date accuracy explains.
Pinpoint your fertile window with our ovulation tool, based on cycle length and last period date. Useful whether you're trying to conceive or tracking your cycle for natural family planning.
Total cholesterol on its own is an incomplete picture. The HDL-to-total ratio is a stronger predictor of cardiovascular risk. Enter your latest blood-test numbers in our cholesterol ratio tool to see where you stand.
The Type 2 diabetes risk tool evaluates the factors most predictive of disease — age, BMI, family history, blood pressure, and activity. If your score is elevated, our guide on early high blood sugar symptoms covers what to watch for.
Not all health calculators are equal. Here's what makes WellCal the most trusted free wellness platform online.
Open the calculator that fits your goal — or browse all thirteen and discover which numbers matter most for your body. Free, instant, no sign-up. Always.
By WellCal Editorial Team , DN-Usama Awan (Reviewer) May 12, 2026 You walked into the kitchen and forgot why. Mid-sentence,
By WellCal Editorial Team , Arwa Khan (Reviewer) May 12, 2026 Your period used to be predictable. Now it’s a
By WellCal Editorial Team , DN-Usama Awan (Reviewer) May 11, 2026 It’s 3:17 AM. Again. Your mind is suddenly racing,
By WellCal Editorial Team , Arwa Khan (Reviewer) May 11, 2026 One moment you’re fine. The next, you’re crying at
By WellCal Editorial Team , DN-Usama Awan (Contributor) May 10, 2026 Updated: May 11, 2026 Your jeans fit fine last
By WellCal Editorial Team , Arwa Khan (Reviewer) May 10, 2026 You sleep eight hours and still drag yourself out