Fitness & Nutrition
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39 Free Calculators · Science-Backed · No Sign-Up

Fitness & Nutrition Calculators For Every Goal

Calculate your TDEE, BMR, macros, body fat, one-rep max, heart rate zones, and more with 39 science-backed calculators. Instant results, no guesswork, and total privacy — everything runs in your browser.

Explore CalculatorsTry TDEE Calculator
39
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7
Categories
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Calculator Categories

Seven focused collections covering every fitness and nutrition calculation — from body composition to race pace to macro planning.

Body Composition & Metrics

Calculate BMI, body fat, ideal weight, and more body metrics.

7 Calculators

Calories & Energy

Find your TDEE, BMR, and track calories burned.

8 Calculators

Macronutrients

Plan your protein, carbs, and fat intake for any goal.

6 Calculators

Hydration

Calculate your daily water needs and sweat rate.

3 Calculators

Strength & Training

Estimate your one-rep max, Wilks score, and plan progression.

5 Calculators

Running & Cardio

Calculate pace, predict race times, and find your heart rate zones.

5 Calculators

Goals & Planning

Plan weight loss timelines, muscle gain, and maintenance calories.

5 Calculators
Most Used

Popular Calculators

The eight calculators people reach for first — proven tools for setting a baseline, hitting your calorie target, and tracking progress.

Calories & Energy

TDEE Calculator

Calculate your tdee

Calculate
Body Composition & Metrics

BMI Calculator

Calculate your bmi

Calculate
Macronutrients

Macro Calculator

Calculate your macro

Calculate
Calories & Energy

Calorie Deficit Calculator

Calculate your calorie deficit

Calculate
Macronutrients

Protein Intake Calculator

Calculate your protein intake

Calculate
Strength & Training

One-Rep Max Calculator

Calculate your one-rep max

Calculate
Running & Cardio

Running Pace Calculator

Calculate your running pace

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Calories & Energy

BMR Calculator

Calculate your bmr

Calculate
Browse All 39 Calculators
Why FitCalcs

Built For Serious Progress

No fluff, no trackers, no upsells — just fast, accurate tools that respect your time and your data.

39 Free Calculators

Comprehensive suite covering every fitness and nutrition calculation you need.

Instant Results

All calculations run instantly in your browser — no waiting, no server calls.

Science-Backed Formulas

Every calculator uses established, peer-reviewed formulas with full methodology transparency.

No Account Required

No sign-ups, no email gates, no paywalls. Just open and calculate.

Three Steps

How It Works

From first visit to actionable numbers in under 60 seconds — no account, no downloads, no waiting.

Step 1

Pick A Calculator

Browse 39 calculators across 7 fitness and nutrition categories.

Step 2

Enter Your Stats

Fill in weight, height, age, activity level, or training details.

Step 3

Get Instant Results

See personalized results immediately — with formula, methodology, and context.

Start With Your Daily Calorie Target

The TDEE Calculator is the foundation of every goal — weight loss, muscle gain, or maintenance. Get your number in 30 seconds.

Calculate TDEE
Mifflin-St Jeor equation
All activity levels
Instant results
No sign-up
Common Questions

Frequently Asked Questions

Everything you need to know about using FitCalcs for your fitness and nutrition planning.

We offer 39 free fitness and nutrition calculators organized into 7 categories: Body Composition (BMI, body fat, ideal weight, etc.), Calories & Energy (TDEE, BMR, calorie burn), Macronutrients (macros, protein, keto, carb cycling), Hydration (water intake, sweat rate), Strength & Training (one-rep max, Wilks score, training volume), Running & Cardio (pace, heart rate zones, VO2 max), and Goals & Planning (weight loss timeline, muscle gain, body recomposition).
Yes. Every calculator on this site is completely free, with no sign-ups, email gates, or paywalls. All calculations run in your browser, so your data never leaves your device. We do not sell or share any user information.
We use only established, peer-reviewed formulas such as Mifflin-St Jeor for BMR, Epley and Brzycki for one-rep max, Karvonen for heart rate zones, and Riegel for race time prediction. Results are estimates that are typically accurate within 5 to 10 percent for most people. Individual results vary based on genetics, body composition, and measurement accuracy.
Most people start with the TDEE Calculator to find their daily calorie needs, then use the Macro Calculator to plan their protein, carbs, and fat intake. If you are new to fitness, the BMI Calculator provides a quick baseline. For weight loss goals, use the Calorie Deficit Calculator. For strength training, the One-Rep Max Calculator is the most popular starting point.
No account is required. The site works entirely in your browser — no registration, no email, no personal data collected. Your calculator inputs and results are never sent to any server or stored beyond your current session.
No. These calculators provide estimates based on general population formulas and are intended for informational and educational purposes only. They are not a substitute for professional medical advice. Always consult a healthcare professional, registered dietitian, or certified trainer before making significant changes to your diet, exercise routine, or health plan.