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Health & Lifestyle Calculators
8 free health calculators for BMI, calories, water intake, sleep cycles, pregnancy due dates, ideal weight, body fat, and running pace. All tools are free, instant, and require no signup.
BMI Calculator
Body Mass Index with healthy weight range, BMI scale, and health category classification.
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Calorie & TDEE Calculator
Daily calorie needs for weight loss, maintenance, or muscle gain. Based on the Mifflin-St Jeor formula.
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Water Intake Calculator
Daily water recommendation based on body weight, activity level, and climate. Shown in cups, oz, and liters.
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Sleep Cycle Calculator
Optimal bedtime and wake-up times based on 90-minute sleep cycles. Wake up refreshed, not groggy.
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Pregnancy Due Date Calculator
Estimated due date, trimester dates, and key pregnancy milestones by last period, conception, or IVF date.
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Ideal Weight Calculator
Healthy weight range using five medical formulas: BMI range, Devine, Robinson, Miller, and Hamwi.
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Body Fat Estimator
Estimate body fat percentage using the US Navy circumference method. Male and female categories included.
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Running Pace Calculator
Calculate running pace, finish time, or distance. Race time predictions for 5K, 10K, half marathon, and marathon.
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Free Health Calculators Built for Everyone
Every tool in this category runs entirely in your browser. Nothing you enter is stored on our servers or visible to us. Your weight, height, measurements, and health data never leave your device. These tools are designed to give you instant, accurate answers without friction — no account, no email address, no cost.
Our health calculators are built on established clinical formulas and reference data:
- BMI uses the WHO standard formula and classification thresholds
- Calorie calculator uses the Mifflin-St Jeor equation, the most accurate BMR formula for the general population
- Water intake is based on the National Academies of Sciences recommendations adjusted for body weight and activity
- Sleep cycle calculator uses the research-backed 90-minute sleep cycle model
- Ideal weight calculator compares five independently derived medical formulas
- Body fat estimator uses the US Navy circumference method, standard in military fitness assessment
⚠️ Medical Disclaimer: All health calculators on Gaugeify are for informational and educational purposes only. Results are estimates and do not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making changes to your diet, exercise routine, or health plan. Full terms →