Calculators
Free nutrition and fitness calculators for the numbers that guide real decisions — daily calories and TDEE, protein and macro targets, BMI, body fat, and water intake. Pick a category, open the tool that fits your goal, and get a clear starting estimate you can actually use.
All calculators
BMI Calculator (Adults: Men & Women)
Enter your height and weight to get your BMI in seconds. Works in kg/cm or lbs/ft; the same categories apply to men and women aged 20+.
02Body Fat Percentage Calculator (U.S. Navy Method)
Measure your waist, neck (and hips for women) with a tape and get a body fat estimate — no scale, no calipers.
03Body Recomposition Calculator: Calories & Protein
Get your maintenance calories and a daily protein target for building muscle while losing fat at the same time — the recomposition approach, from your age, weight and activity.
04Butter and Oil Substitute Calculator
Swap butter for oil, or either one for a fruit purée, and get the amount that works plus what it does to the calories and fat. Some of these replace all the fat, most replace half.
05Buttermilk Substitute Calculator
No buttermilk? Enter how much your recipe needs and pick what you have. You get the exact amounts to mix, how long to leave it, and where the substitute will not pass for the real thing.
06Caffeine Calculator: How Much Caffeine in Your Day?
Add up the coffee, tea, energy drinks and soda in your day and see your total caffeine against the 400 mg daily safe limit — with what to do if you go over.
07Calorie Deficit Calculator: How Many Calories to Lose Weight
Tell the calculator your current weight, goal and activity. It returns a daily calorie target, the size of your deficit and a realistic timeline.
08Calorie Surplus (Bulking) Calculator
Get a daily calorie target above maintenance sized for muscle gain, not fat gain — with the expected weekly weight change.
09Carb Cycling Calculator (7-Day Plan)
Choose how many high, moderate and low-carb days you want; get calories and macros for each type and a weekly plan.
10Cups to Grams Converter: Flour, Sugar, Butter and More
Pick an ingredient and see exactly what a cup, tablespoon or teaspoon weighs in grams — flour, sugar, butter, oil, milk and more. Plus the calories and macros of that amount, from our USDA food data.
11Daily Calorie Calculator: How Many Calories Should I Eat?
Get your maintenance calories, plus targets for losing or gaining weight, from your age, sex, height, weight and activity level.
12Egg Substitute Calculator for Baking
Choose how many eggs your recipe calls for and what you want to use instead. You get the exact amount to make, what that substitute does and does not do, and where it will not work.
13Fiber Intake Calculator: Daily Target & Food Tracker
Find your daily fiber target by age and sex, then tally real foods to see how close you are — with fiber values straight from our food database.
14Flour Substitute Calculator
Tell it how much all-purpose flour your recipe calls for. It works out how much you can actually replace with the flour you have, what to add so the recipe still works, and what changes nutritionally.
15Ideal Body Weight Calculator (Height, Sex & Frame)
See what four standard formulas say your ideal weight is for your height — and the healthy BMI range, which is usually the more useful answer.
16Intermittent Fasting Calculator (16:8, 18:6, 20:4, OMAD)
Choose a fasting schedule and your first meal time; get your eating window and the calories to eat inside it.
17Keto Macro Calculator: Fat, Protein & Net Carbs
Set your carb limit and goal; get grams of fat, protein and net carbs for the day.
18Lean Body Mass & FFMI Calculator
Enter weight, height and body fat percentage to get your lean body mass in kg/lb and your FFMI — the muscle-per-height score.
19Macro Calculator: Daily Protein, Carbs & Fat
Your calories, split into grams of protein, carbohydrate and fat for your goal. Pick a preset or set your own ratio.
20Meal Calorie Calculator: Calories per Meal
Enter your daily calories and how many meals you eat; get a target for each meal, with protein, carbs and fat.
21Protein Intake Calculator: How Much Protein Do You Need?
Enter your weight, activity and goal to get a daily protein target in grams — and see how it splits across meals.
22Reverse Dieting Calculator
Enter your current dieting calories and estimated maintenance; get a week-by-week plan for adding calories back.
23Sugar Substitute Calculator for Baking
Swap sugar for stevia, erythritol, monk fruit, allulose or honey and get the amount that matches in sweetness — in cups or grams. The calculator also shows what happens to the calories, and where a swap will not behave like sugar.
24TDEE Calculator: Total Daily Energy Expenditure
Your TDEE is the number of calories you burn in a day. Enter your details and activity level to estimate it and see what to eat to maintain, lose or gain.