Free Health Tools

14 interactive calculators built on published US data and peer-reviewed research. Every tool runs entirely in your browser: no signup, no stored answers, no gimmicks.

Built on published 2026 US data

Reviewed by our health writers

Private: nothing you enter is stored

Dental cost calculators

Dental Implant Cost CalculatorReal 2026 US price ranges by treatment type, region, add-ons, and insurance.By Dr. Sage Wells

Invisalign vs Braces Cost CalculatorCompare aligners with metal, ceramic, and lingual braces for your case and region.By Dr. Sage Wells

Teeth Whitening Cost CalculatorIn-office, laser, custom trays, and strips compared by city and stain level.By Dr. Sage Wells

Skin tools

What Is On Your Skin? Removal GuidePick the glue, dye, wax, tar or paint you spilled and get the solvent that works, what to avoid, and how long it takes.By Nico Jae

Sleep tools

Caffeine Half-Life CalculatorSee how much caffeine is still in your system at bedtime, plus your personal cutoff time.By Nico Jae

Sleep Debt CalculatorMeasure your weekly sleep debt against AASM guidelines and get a recovery plan.By Nico Jae

Fitness and body tools

Steps to Miles CalculatorConvert steps to miles with your exact stride length, plus calories burned.By Chris Leo

Waist-to-Height Ratio CalculatorThe health check that beats BMI, with your BMI included for context.By Chris Leo

Lean Body Mass CalculatorBoer, James, and Hume formulas plus their average, with implied fat mass.By Chris Leo

Max Heart Rate + Zones CalculatorResearch-backed Tanaka formula with all five training zones in bpm.By Chris Leo

Walking Calorie CalculatorCalories burned by your weight, pace, time, and hills, from published MET data.By Chris Leo

Nutrition and hydration tools

Fasting CalculatorMap 16:8, 18:6, OMAD, and more onto your real daily schedule.By Chris Leo

Protein CalculatorYour daily gram range for fat loss, muscle gain, endurance, or general health.By Chris Leo

Water Intake CalculatorA realistic daily water target from your weight, activity, and climate.By Chris Leo

Women’s health tools

Period CalculatorPredict your next three periods privately: everything stays in your browser.By Dr. Sage Wells

Coming soon

Coming soonMacro CalculatorDaily protein, carb, and fat split for your goal, built on your TDEE.

Coming soonBody Fat Calculator (US Navy)Tape-measure method used by the US Navy, no calipers needed.

Coming soonTDEE CalculatorMaintenance calories with BMR and safe-deficit tabs in one tool.

For your safety

Estimate disclaimer: These tools provide educational estimates based on published data and standard formulas. They are not quotes, diagnoses, or medical advice. Costs, health needs, and results vary by individual; always confirm with a licensed professional.

Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.