Screen your numbers
Estimate BMI, ideal weight, and calorie needs with clearly stated assumptions.
Health & fitness calculators
Health & Fitness Calculators for Weight, Body, Calories, and Pacing
Estimate body metrics, daily calorie needs, due dates, and pacing with transparent screening tools that state their methods and limits.
Built for people tracking weight or fitness, runners, expectant parents, and health-conscious planners. Inputs stay local unless a tool clearly says otherwise.
Decision support
Use these tools before money changes hands
Plan a goal
Set a weight, pace, or study target and check what inputs drive the result.
Understand the limits
Health screening tools are general estimates, not diagnoses.
Tool cluster
Recommended tools
Featured
BMI Calculator
bmi calculator that computes body mass index from height and weight, with healthy ranges by age for men and women. Free, private, runs locally in your browser.
Featured
Calorie Calculator
calorie calculator that estimates daily calorie needs and macros from age, weight, and activity level using Mifflin-St Jeor. Free, runs locally, no signup.
Featured
Ideal Weight Calculator
Ideal weight calculator by height: compare the Devine, Robinson, Hamwi, and Miller formulas side by side and see why they disagree. Free, runs in your browser.
Featured
Pace Calculator
Running pace calculator: convert race time and distance into pace per km or mile, and predict marathon or 5K finish times. Free, private, no signup required.
Useful
Pregnancy Calculator
Pregnancy calculator: find your due date, current week of pregnancy, and estimated conception date from your last period. Free, in your browser, no signup.
Useful
Body Fat Estimate Calculator
Body fat calculator: estimate your body fat percentage from simple body measurements using the US Navy method, with lean mass. Free, private, no signup.
Useful
Waist to Height Ratio Calculator
Waist to height ratio calculator: divide waist circumference by height to assess central fat health risk. Instant result, no signup, private, free in browser.
Useful
Heart Rate Zones Calculator
Heart rate zones calculator: turn your age or max heart rate into five training zones with target bpm ranges for every workout intensity. Free, no signup.
Useful
Sleep Debt Calculator
Sleep debt calculator: compare your actual nightly sleep against your personal sleep need over a week and see hours owed plus recovery time. Free, private.
Useful
Daily Water Intake Calculator
Daily water intake calculator: estimate how much water you need per day from weight, activity, and climate. Free, private, no signup, runs in your browser.
Useful
Maintenance Calories Calculator
Maintenance calories calculator: compute your daily calories to maintain weight from age, height, weight, and activity level. Free, private, no signup.
Useful
Calorie Deficit Calculator
Calorie deficit calculator: set a goal weight and date and get your daily calorie target plus expected weekly loss. Free, private, no signup required.
Useful
UV Exposure Calculator
UV exposure calculator that estimates safe sun exposure time from the UV index and your skin type before you go outside. Free, no signup, runs in your browser.
Useful
Steps to Miles Calculator
Steps to miles calculator: convert your daily step count into miles or kilometers using your height and stride length. Free, private, no signup, runs locally.
Trust model
Useful pages, not thin pages
These collections group existing tools around real decisions. The calculators keep assumptions visible, link to related tools, state important limitations, and point toward quality evidence so you can verify inputs before relying on a result.
FAQ
Common questions
Are these health tools a diagnosis?
No. They are general screening and planning estimates with stated methods and limitations. Consult a qualified professional for health advice.
How accurate are BMI and calorie estimates?
They use standard formulas and published defaults. Individual factors like body composition, activity, and medical conditions can change results.
Which calculator is right for me?
Pick the metric you want to estimate — BMI, calories, ideal weight, pace, or due date — and use the related links to compare.