Free Fitness Calculators & Tools for Lifters

Access our collection of science-backed fitness calculators designed specifically for weightlifters, bodybuilders, and strength training enthusiasts. Whether you're planning a cutting phase, bulking cycle, or just want to track your macros and PRs, our free tools will help optimize your training and nutrition.

Why Use Our Fitness Calculators?

Each calculator uses scientifically-validated formulas tailored specifically for lifters. Unlike generic fitness calculators, our tools account for factors most relevant to strength athletes and bodybuilders.

Training Calculators

1RM Calculator

Accurately estimate your one-rep max using multiple proven formulas without risking injury from actual max attempts.

Find Your 1RM

RPE Calculator

Calculate optimal training weights using Rate of Perceived Exertion (RPE) for auto-regulating intensity based on daily readiness.

Calculate RPE Loads

Strength Standards Calculators

Strength Standards

Compare your bench press, squat, and deadlift to comprehensive strength standards from Untrained to Elite based on age, gender, and bodyweight.

Check Strength Standards

Bench Press Standards

Find your max bench press and see how you compare to strength standards from Untrained to Elite based on age, gender, and bodyweight.

Check Your Bench

Squat Standards

Calculate your max squat and compare your results to proven strength standards from Untrained to Elite based on age, gender, and bodyweight.

Check Your Squat

Deadlift Standards

Find your max deadlift and see how you rank against comprehensive strength standards from Untrained to Elite based on age, gender, and bodyweight.

Check Your Deadlift

Nutrition Calculators

Bulking Calculator

Calculate your optimal caloric surplus and macronutrient breakdown for maximum muscle growth with minimal fat gain.

Plan Your Bulk

Cutting Calculator

Determine your optimal caloric deficit and macro splits for maximum fat loss while preserving hard-earned muscle mass.

Calculate Cutting Plan

Macro Calculator

Compute your BMR, TDEE and precise macronutrient targets whether you're cutting, bulking, or maintaining.

Calculate Macros

Track Your Progress with Gravitus

Maximize your fitness results. Research shows that tracking your workouts and nutrition leads to significantly better results. Visualize your progress, monitor trends, and stay motivated with data-driven insights.

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How to Use Our Fitness Calculators

Each of our strength training and bodybuilding calculators is designed to be easy to use while providing precise, actionable information. Here's how to get the most out of our tools:

1

Input Accurate Measurements

For the most accurate results, measure your current weight, height, and if possible, body fat percentage. Be honest about your activity level - most people overestimate this.

2

Choose Appropriate Goals

For bulking, aim for 0.25-0.5% body weight gain per week. For cutting, target 0.5-1% body weight loss weekly. These ranges optimize results while minimizing muscle loss or excess fat gain.

3

Monitor and Adjust

Use the calculator results as your starting point, then track your progress for 2-3 weeks. If you're not seeing expected results, make small adjustments to your calories (±200) and reassess.

4

Track Your Progress

For optimal results, use these calculators in conjunction with consistent tracking of your workouts, nutrition, and body measurements. The Gravitus app makes this seamless and visual.

Fitness Calculator FAQ

Our calculators use scientifically-validated formulas specifically chosen for strength athletes and bodybuilders. While they provide accurate starting points, individual factors like metabolism, genetic factors, and non-exercise activity can influence your actual needs. We recommend using the calculator results as a starting point, then adjusting based on your measured progress over 2-3 weeks.

  • Cutting Calculator: Use when your primary goal is fat loss while preserving muscle mass
  • Bulking Calculator: Use when your primary goal is muscle gain while minimizing fat accumulation
  • Macro Calculator: The most versatile option that can be used for cutting, bulking, or maintenance phases
The specialized calculators (cutting and bulking) include phase-specific recommendations tailored to those goals.

For most lifters, the Mifflin-St Jeor equation provides the most accurate BMR estimation according to research. For leaner individuals (below 15% body fat for men or 22% for women), the Katch-McArdle formula, which factors in lean body mass, often provides better accuracy. Our advanced calculator modes use these formulas along with activity modifiers specifically tailored to weight training rather than general fitness.

For optimal results, we recommend tracking several metrics weekly:
  • Body weight (measured first thing in the morning)
  • Body measurements (waist, chest, arms, legs)
  • Progress photos (same lighting and time of day)
  • Training performance (strength improvements)
  • Energy levels and recovery quality
The Gravitus app offers comprehensive tracking for all these metrics, providing visual data on your progress over time.

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