Free Online Calculators
Browse all 30 science-backed calculators. Filter by category or search to find exactly what you need.
Calorie Calculator
Calculate your daily calorie needs based on age, gender, weight, height, and activity level using the Mifflin-St Jeor equation. Free and accurate.
TDEE Calculator
Calculate your Total Daily Energy Expenditure (TDEE) with precision. Factor in BMR, activity level, and exercise to find your true calorie burn.
Macro Calculator
Calculate your ideal macronutrient split for weight loss, muscle gain, or maintenance. Get personalized protein, carb, and fat targets in grams.
Protein Calculator
Find your optimal daily protein intake based on body weight, activity level, and fitness goals. Uses ISSN and WHO evidence-based guidelines.
BMI Calculator
Calculate your Body Mass Index (BMI) and see where you fall on the WHO health range chart. Supports both metric and imperial units instantly.
Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy method with neck, waist, and hip measurements. See healthy body fat ranges by age and sex.
Water Intake Calculator
Calculate how much water you should drink daily based on your weight, activity level, and climate. Science-backed hydration recommendations.
Calorie Deficit Calculator
Calculate your ideal calorie deficit for safe, sustainable weight loss. See how long it takes to reach your goal weight with a personalized plan.
IF Calculator
Calculate your intermittent fasting schedule with custom eating windows. Choose from 16:8, 18:6, 20:4, or OMAD protocols with calorie targets.
Meal Plan Calculator
Split your daily calories across meals and snacks with a custom meal plan calculator. Choose 3-6 meals per day with balanced macro distribution.
1RM Calculator
Calculate your one rep max for any lift using the Epley, Brzycki, or Lombardi formulas. Get accurate strength estimates from your working sets.
Running Pace Calculator
Calculate your running pace, finish time, or distance for any race. Supports 5K, 10K, half marathon, and marathon with split predictions.
Calories Burned Calculator
Calculate calories burned during 100+ exercises including running, walking, cycling, swimming, and strength training. Based on MET values.
Steps to Calories
Convert your daily step count into calories burned. Factor in your weight, pace, and terrain for an accurate walking calorie burn estimate.
Rest Day Calculator
Calculate how many rest days you need per week based on training intensity, volume, experience, and sleep quality. Prevent overtraining now.
Heart Rate Zones
Calculate your five heart rate training zones based on max heart rate or the Karvonen formula. Optimize fat burn, endurance, and performance.
VO2 Max Calculator
Estimate your VO2 max using the Cooper test, Rockport walk test, or running performance. See your cardiorespiratory fitness level and percentile.
Lean Body Mass Calculator
Calculate your lean body mass (fat-free mass) using the Boer formula. Essential for setting protein targets and tracking body recomposition.
Pregnancy Weight Gain
Track your pregnancy weight gain by trimester against IOM guidelines. See if you are on track for a healthy pregnancy based on your pre-pregnancy BMI.
Postpartum Calories
Calculate your daily calorie needs postpartum for safe recovery and gradual weight loss. Accounts for breastfeeding status and activity level.
Ovulation Calculator
Predict your ovulation date and fertile window based on your cycle length. Track your most fertile days for conception or natural family planning.
Period Tracker
Predict your next period date and cycle length based on your menstrual history. Track cycle regularity and identify patterns over time.
Baby Food Portions
Calculate age-appropriate baby food portion sizes from 4-24 months. Based on AAP and WHO complementary feeding guidelines for healthy infants.
Breastfeeding Calories
Calculate your daily calorie needs while breastfeeding based on feeding frequency, baby's age, and your weight loss goals. Stay nourished safely.
Ideal Weight Calculator
Calculate your ideal weight range using Devine, Robinson, Miller, and Hamwi formulas. See healthy weight ranges customized by height and frame size.
Budget Calculator
Build a monthly budget using the 50/30/20 rule. Allocate your income to needs, wants, and savings with a personalized budget breakdown instantly.
Savings Goal Calculator
Calculate how much to save monthly to reach your financial goal by your target date. Factor in interest and existing savings for an exact plan.
Debt Payoff Calculator
Compare debt snowball vs avalanche strategies. See your payoff date, total interest paid, and monthly payment plan for each method side by side.
Grocery Budget
Calculate a realistic monthly grocery budget based on household size, diet type, and USDA food plan tiers. Plan your food spending with confidence.
Meal Prep Cost
Calculate the cost per meal for your meal prep recipes. Compare meal prepping costs vs eating out and see your monthly savings potential.