Health & Fitness Calculators

Estimate BMI, calories, fertility dates, and common health-planning metrics.

12 tools available
Practical calculators
Built for browser use
Guides included
12 tools available
Practical calculators
Built for browser use
Guides included

Popular workflows

Useful paths through this category

Follow a short workflow when one calculator naturally leads to another.

Body metrics

Compare BMI with body fat and ideal-weight estimates while keeping limitations visible.

Nutrition planning path

Estimate daily calories, split macros, and check ingredient-level nutrition examples.

Training intensity

Estimate heart-rate zones for general fitness planning and Zone 2 context.

Cycle and pregnancy estimates

Use date-based tools for cycle, ovulation, and due-date planning while keeping medical limits clear.

Category note

Health and fitness calculators are educational estimates, not medical advice or diagnosis. Ask a qualified professional about medical concerns, pregnancy, medications, symptoms, eating-disorder history, or health conditions.

Popular

BMI Calculator

Calculate adult BMI from height and weight with cautious screening-category context.

Check BMI

Calorie Calculator

Estimate a maintenance-energy range from resting energy and a disclosed activity band.

Calculate Calories
New

Macro Calculator

Convert entered calories and macro percentages into protein, carbohydrate, and fat grams.

Calculate Macros

Body Fat Calculator

Estimate body fat percentage from defined circumference measurements with a historical equation.

Check Body Fat

Ideal Weight Calculator

Compare historical adult reference-weight equations with separate results and clear limitations.

Check Weight

Chipotle Calorie Calculator

Add U.S. Chipotle calories and macros from published ingredient serving values.

Build Meal

BMR Calculator

Estimate resting energy with the Mifflin-St Jeor equation and transparent assumptions.

Calculate BMR

Pregnancy Due Date Calculator

Estimate a due date from an entered last menstrual period using a transparent 280-day method.

Calculate Due Date

Ovulation Calculator

Estimate one ovulation date and six-day fertile window from a period start and cycle length.

Check Ovulation

Period Calculator

Project one estimated period start and inclusive end date from cycle and period lengths.

Track Period

Water Intake Calculator

Show population-based total-water references for water from foods and beverages.

Calculate Water

Sleep Calculator

Plan a bedtime or wake time from an entered duration with deterministic midnight rollover.

Calculate Sleep

Lean Body Mass

Calculate estimated lean body mass and fat mass from weight and entered body fat.

Calculate LBM

What this category helps with

Use Health & Fitness calculators for BMI and body-composition estimates, calorie and macro planning, heart rate zones and Zone 2 training, ideal weight context, and fast-food nutrition estimates such as Chipotle calories.

Common tasks

  • Compare BMI, body fat, lean mass, and ideal-weight estimates.
  • Estimate BMR, TDEE, maintenance calories, macros, and nutrition totals.
  • Check heart rate zones, max heart rate, Zone 2 ranges, hydration, and sleep timing.
  • Estimate cycle, ovulation, and due-date timing for general planning, not diagnosis or treatment.

Why Calzivo makes it easier

Health pages keep assumptions visible and use neutral wording so BMI, calories, macros, body fat, heart-rate, and nutrition estimates are easier to compare without becoming medical claims.

Frequently Asked Questions

Questions about health and fitness estimates, input assumptions, calculator limits, and when to ask a qualified professional.