Intermittent Fasting Calculator, MD-Verified 2026
MD-verified intermittent fasting calculator with personalized eating windows, sleep-overlap analysis, protocol comparison, and a full 7-day fasting schedule — updated March 2026.
Calculators
Pregnancy Weight Gain Calculator by Week and Trimester
Calculate your healthy pregnancy weight gain by week and trimester. Based on IOM & ACOG 2026 guidelines — personalised for your BMI, singleton or twins.
Heart Rate Zone Calculator by Age: Find Your Exact Fat Burn, Cardio & Peak Zones (Plus Medical Safety Guide)
Stop guessing your training zones. This free calculator finds all 5 heart rate zones by your exact age and resting heart rate — including the Zone 2 fat burn sweet spot that cardiologists recommend, plus medication warnings fitness apps never warn you about.
Running Pace Calculator: Find Your Exact Pace for Miles, KM & Every Race Distance — Will You Hit Your Goal Time?
You've got a goal finish time. Now you need to know: is your current pace fast enough to get there? Enter your distance and time — get your exact pace per mile and km, full race splits, and the training pace you need to run right now to hit your goal.
1RM Calculator: How Strong Are You Really? Calculate Your True One Rep Max With 7 Scientific Formulas
Most lifters are training with the wrong weights — because they're guessing their 1RM. This free calculator uses 7 research-backed formulas to find your true one rep max in seconds, then gives you exact training percentages for strength, hypertrophy and power. No gym testing required.
Macro Calculator: What Should You Actually Be Eating Each Day? Get Your Perfect Protein, Carbs & Fat Split in 60 Seconds
Most people have no idea how much protein, carbs or fat their body actually needs — they're just guessing. This free macro calculator takes your stats, goal and activity level and spits out your exact daily macros in 60 seconds. Fat loss, muscle gain, maintenance — personalized for you, not a generic template.
Body Fat Percentage Calculator (Navy Method): Are You Actually Healthy—or Just a Normal Weight?
BMI told millions of people they were healthy. Body fat testing told a different story. This free Navy Method calculator reveals your true body fat percentage in seconds — your health risk category, exact lean vs. fat mass, and the precise fat loss target doctors actually use. No gym equipment needed. Just a tape measure.
Protein Intake Calculator: How Much You Actually Need — Why the 0.8g/kg RDA Is a Minimum, Not a Target
The government's 0.8g/kg protein RDA is the minimum to prevent malnutrition — not the amount you need to build muscle, lose fat or stay healthy as you age. Enter your weight, goal and activity level to get your personalized daily protein target, from sedentary maintenance (1.0g/kg) to serious athlete training (up to 2.7g/kg). Instant, science-backed, free.
Water Intake Calculator: Find Your Exact Daily Hydration Target Based on Weight, Activity & Climate
The "8 glasses a day" rule is outdated — your real water needs depend on your weight, activity level and climate. This free calculator gives your exact daily target in seconds, explains why dehydration symptoms appear before you feel thirsty, and shows how hydration directly affects your energy, focus and metabolism.
Ideal Weight Calculator: Is Your Current Weight Actually Healthy? Find Your True Range Using 4 Medical Formulas
BMI alone doesn't tell the full story — a muscular person can be "overweight" while someone "normal" weight can still carry dangerous fat levels. Enter your height, age and sex to get your ideal weight range from 4 validated medical formulas, plus a clear verdict on where you actually stand.