Free Health Calculators & Tools
Get instant, accurate health insights based on scientific formulas — private, instant, no signup.
- 53 Free tools
- 9 Health categories
- 100% Free · no signup
Popular tools
- Nutrition
Intermittent Fasting Calculator & Timer
Pick a protocol (16:8, 18:6, OMAD, 5:2), set your eating window, and run a live fasting timer. Open - Nutrition
7-Day Meal Plan Generator
Turn your calorie and macro targets into a free, personalized week of meals with a grocery list. Open - Nutrition
Muscle Preservation Calculator
Keep muscle while losing weight — get your protein target, a muscle-loss risk check, and an action plan. Open - Nutrition
Calorie Calculator
Find your daily calorie target (TDEE) for losing, maintaining, or gaining weight. Open - Nutrition
Macro Calculator
Split your calories into protein, carbs, and fat that fit your goal. Open - Nutrition
Water Intake Calculator
Find how much water to drink each day, in liters and fluid ounces. Open
Explore tool categories
From nutrition to heart health, find the right calculator for whatever you’re working on.
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Nutrition
Calories, macros, and daily intake targets.
9 tools -
Body & Weight
BMI, body fat, and healthy weight ranges.
9 tools -
Fitness
Training pace, strength, and performance.
8 tools -
Heart Health
Heart rate zones, max HR, and blood pressure.
4 tools -
Metabolic Health
Hydration, metabolism, and energy use.
2 tools -
Sleep & Recovery
Sleep cycles, naps, and sleep debt.
6 tools -
Women's Health
Cycle, ovulation, and pregnancy tools.
5 tools -
Health Risk
Educational risk estimates — not a diagnosis.
6 tools -
Mental Wellness
Self-reflection check-ins and calming tools.
4 tools
Trustworthy by design
HealthyLifeStyles is built on transparent science and real privacy — so you can rely on the numbers and keep your data your own.
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Scientific formulas
Every result comes from established, peer-reviewed equations used by clinicians and researchers — not guesswork.
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Sources cited
We show the exact formula and link the original research on each tool page, so you can verify the method yourself.
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No data stored
Calculations run entirely in your browser. The numbers you enter are never uploaded, saved, or sold.
Frequently asked questions
Everything you need to know about using our tools.
Are the health calculators free to use?
Yes. Every calculator and tool on HealthyLifeStyles is completely free, with no signup, subscription, or paywall. You can use them as often as you like.
Do I need to create an account?
No account is required. The tools run instantly in your browser — just enter your numbers and get your result.
Is my data stored or shared?
No. The values you enter are processed in your browser to show your result and are never sent to a server, stored, or shared with anyone.
How accurate are the results?
Each tool uses established, peer-reviewed scientific formulas (such as Mifflin-St Jeor for metabolism and the U.S. Navy method for body fat) and we cite the source on every tool page.
Can I use these tools for medical decisions?
Our tools are for general education and wellness only and are not a substitute for professional medical advice. Always consult a qualified healthcare provider before making health decisions.
Which units do the calculators support?
All tools support both metric (kg, cm) and imperial (lb, ft/in) units, so they work for users in the US, UK, Canada, Australia, and beyond.
Still have a question? Get in touch.
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