BMI is a useful screening tool but does not account for muscle mass, bone density, or fat distribution. Athletes may have a high BMI despite being healthy.

How many calories should I eat to lose weight?

A deficit of 500 calories per day below your TDEE typically results in about 1 pound of weight loss per week. Use the TDEE Calculator to find your baseline.

How much protein do I need daily?

General recommendations are 0.8g per kg of body weight for sedentary adults and 1.2-2.0g per kg for active individuals. Use the Protein Calculator for a personalized estimate.

How much water should I drink per day?

A common guideline is eight 8-oz glasses (about 2 liters), but needs vary based on weight, activity level, and climate. The Water Intake Calculator provides a personalized recommendation.

Health & Nutrition Calculators — Free Online Tools (2026)

Take control of your nutrition and wellness with these health calculators. From understanding your BMI to dialing in your macros, these tools give you the data you need to make informed decisions about your diet and health goals.

All Calculators

BMI Calculator — Free Body Mass Index Calculator Online

Calculate your Body Mass Index (BMI) instantly with our free calculator. Enter your height and weight to find your BMI category and health range.

Calorie Calculator — Free Daily Calorie Estimator

Estimate your daily calorie needs for weight loss, maintenance, or gain based on age, sex, height, weight, and activity level.

TDEE Calculator — Total Daily Energy Expenditure

Calculate your Total Daily Energy Expenditure based on BMR and activity level to plan your diet and fitness goals.

Macro Calculator — Protein, Carbs & Fat Calculator

Calculate your daily macronutrient targets for protein, carbs, and fat based on your calorie goal and diet type.

Protein Calculator — Daily Protein Needs Estimator

Calculate your recommended daily protein intake based on body weight, activity level, and fitness goals.

Water Intake Calculator — Daily Hydration Guide

Calculate how much water you should drink daily based on your body weight, activity level, and climate conditions.

Ideal Weight Calculator — Healthy Weight by Height

Find your ideal body weight using the Devine, Robinson, Miller, and Hamwi formulas based on your height and sex.

How to Use These Tools Together

1
Start by calculating your Body Mass Index to understand where you fall on the weight spectrum.
2
Determine a healthy target weight based on your height, age, and gender.
3
Calculate your Total Daily Energy Expenditure to know how many calories you burn each day.
4
Break your calorie target into optimal protein, carbohydrate, and fat ratios.
5
Estimate how much water you should drink daily based on your weight and activity level.

Key Terms Glossary

BMI: Body Mass Index, a measure of body fat based on height and weight used to screen for weight categories.
TDEE: Total Daily Energy Expenditure, the total number of calories your body burns in a day including activity.
BMR: Basal Metabolic Rate, the number of calories your body burns at rest to maintain basic life functions.
Macronutrients: The three main nutrients your body needs in large amounts: protein, carbohydrates, and fat.
Caloric Deficit: Consuming fewer calories than your body burns, which is required for weight loss.
Caloric Surplus: Consuming more calories than your body burns, which is required for muscle or weight gain.

Frequently Asked Questions

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