Every James Smith Calculator, In One Place
Seven free, science-backed calculators to help you hit your goal — whether that’s losing fat, building muscle, or just knowing your daily numbers. Pick one below and get instant results.
Your full TDEE, calorie target and complete macro breakdown — protein, carbs and fats — in under 60 seconds.
Use This Calculator →Find your exact daily calorie deficit for steady, sustainable fat loss — without the guesswork or crash diets.
Use This Calculator →Get your lean calorie surplus and protein target to build muscle while keeping fat gain to a minimum.
Use This Calculator →Work out exactly how many calories you need each day to maintain, lose, or gain weight based on your activity level.
Use This Calculator →Calculate the right amount of daily protein for your body weight and goal — fat loss, muscle gain, or maintenance.
Use This Calculator →Discover the exact calorie deficit you need for safe, steady weight loss — without losing muscle or slowing your metabolism.
Use This Calculator →Get your personalised protein, carb and fat targets in grams — tailored to your body and your training goal.
Use This Calculator →All seven calculators are 100% free, require no sign-up, and use the Revised Harris-Benedict Formula — trusted for accurate, science-backed results.