🏥 Health Calculators
All 9 free health calculators in one place — Hit your targets with 9 free health calculators — BMI & Body Composition, Calorie & TDEE Deficit, and the HDHP vs PPO Out-of-Pocket tool for fitness goals and smarter insurance picks.. Every tool runs 100% client-side in your browser: no sign-up, no uploads, instant answers.
Last updated: September 2026 · 9 free tools
The Complete Guide to Health Calculators
Good health decisions start with honest numbers — what you burn, what coverage actually costs, and how much protection your family needs. This hub gathers 9 free health calculators spanning fitness, health insurance, and financial protection. They are quick, private (everything runs in your browser), and built to turn vague goals into concrete targets.
Fitness: train with targets, not guesses
The BMI & Body Composition calculator gives you a baseline using the standard adult categories, while the Calorie & TDEE Deficit tool estimates your total daily energy expenditure and the intake range for your goal — whether that is losing, maintaining, or gaining. Hydration matters more than most people think: the Daily Water Intake calculator personalizes it by weight and activity. Movers get the Steps to Miles & Kilometers converter, and lifters get the Bench Press & 1RM Max estimator for programming progressive overload safely.
Insurance: pick the plan that costs least for you
Open enrollment is a math problem disguised as paperwork. The HDHP vs PPO Out-of-Pocket calculator compares total yearly cost — premiums plus expected care — so you can see which plan wins at your level of doctor visits. The HSA vs FSA Tax Savings tool quantifies the tax break on medical spending (an HSA’s triple tax advantage is one of the best deals in the tax code for those who qualify), and the COBRA Health Insurance calculator prices continuation coverage after a job change so the sticker shock does not catch you off guard.
Protection: the math nobody wants to do
The Life Insurance Needs (DIME) calculator sizes coverage from the DIME formula — Debt, Income, Mortgage, and Education — so your family’s number is calculated, not guessed.
Putting the tools to work together
These calculators are most powerful in combination. Training toward a goal? Get your baseline from the BMI calculator, set your intake with the Calorie & TDEE tool, and check hydration with the Water Intake calculator — three numbers that turn “get in shape” into an actual plan. Facing open enrollment? Run the HDHP vs PPO comparison using last year’s real doctor visits and prescriptions, then layer the HSA vs FSA tool on top: many people discover the high-deductible plan plus HSA contributions beats the PPO by hundreds of dollars a year. Between jobs, price COBRA against marketplace alternatives before a coverage gap forces a rushed decision — COBRA lets you keep your doctors and your progress toward the deductible, but you pay the full premium plus up to a 2% administrative fee, so the monthly number can sting.
How to pick the right tool
Training toward a goal: BMI, Calorie/TDEE, Water Intake, and 1RM. Facing open enrollment: HDHP vs PPO plus HSA vs FSA. Between jobs: COBRA. Protecting a family: Life Insurance (DIME). One honest note: these calculators are informational only, not medical advice — talk to your doctor before changing diet, training, or treatment, and to a licensed agent for coverage decisions.
🏥 All 9 Health Calculators
Every tool below is free, unlimited, and runs entirely in your browser — pick the one that matches your question.
Estimate One-Rep Max using the Epley and Brzycki strength formulas with sub-maximal repetition sets.
Calculate BMI score and healthy weight ranges for adults according to official CDC height/weight standards.
Determine Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure for weight loss, maintenance, or muscle gain.
Calculate monthly COBRA continuation premiums after leaving an employer, including the 102% statutory employer subsidy transfer.
Calculate worst-case medical expenses, deductible milestones, coinsurance splits, and ACA maximum out-of-pocket limits for High Deductible Health Plans.
Compare Health Savings Accounts (HSA) with Flexible Spending Accounts (FSA). Calculate triple-tax savings, rollover compounding, and medical expense shields.
Calculate exact term life insurance required using the certified DIME formula: Debt, Income, Mortgage, and Education.
Convert walking steps to miles, kilometers, and estimated active calories burned based on your height and stride length.
Calculate recommended daily water consumption in ounces and liters based on body weight, climate, and exercise.
Health Calculator FAQs
Straight answers to the questions people ask most about health calculators.
What is considered a healthy BMI?
For adults, the standard categories are: under 18.5 underweight, 18.5–24.9 healthy weight, 25–29.9 overweight, and 30+ obese. BMI is a screening tool, not a diagnosis — athletes with high muscle mass can score ‘overweight’ while being perfectly fit. The BMI & Body Composition calculator gives you the number; your doctor gives you the context.
How many calories should I eat to lose weight?
Sustainable fat loss generally comes from eating moderately below your TDEE (total daily energy expenditure) — the Calorie & TDEE Deficit calculator estimates yours from your stats and activity. Crash diets backfire; aim for a steady, maintainable deficit and check with a professional if you have medical conditions.
HDHP or PPO — which health plan should I choose?
It depends on how much care you use. HDHPs have lower premiums but higher deductibles and pair with an HSA; PPOs cost more monthly but less per visit. If you rarely see a doctor, the HDHP often wins on total cost; with chronic conditions or planned procedures, the PPO frequently wins. The HDHP vs PPO calculator compares your total yearly cost under each.
What makes an HSA better than an FSA?
An HSA offers a rare triple tax advantage: pre-tax contributions, tax-free growth, and tax-free withdrawals for medical expenses — plus the balance rolls over forever and stays with you if you change jobs. FSAs are use-it-or-lose-it and tied to your employer. The HSA vs FSA calculator quantifies the difference for your bracket.
How much life insurance do I actually need?
A solid starting framework is DIME: add up outstanding Debt, 10x annual Income, remaining Mortgage balance, and expected Education costs, then subtract existing assets. The Life Insurance Needs (DIME) calculator walks through it — most families are surprised the number is higher than their gut feeling.
Is this medical advice?
No. These calculators are informational tools for planning and education. They do not diagnose, treat, or replace professional judgment — consult your doctor, dietitian, or licensed insurance agent before acting on health or coverage decisions.