How to Use
- 1.
Enter age, sex equation option, height, and current weight using metric or imperial units.
- 2.
Select an activity level and BMR formula; enter body-fat percentage only if you want to try Katch–McArdle.
- 3.
Choose fat loss, maintenance, or build/gain and review the moderate calorie adjustment.
- 4.
Select a macro ratio preset or customize the sliders; they remain normalized to 100%.
- 5.
Review estimated calories, BMR, TDEE, daily grams, and the optional per-meal arithmetic split.
- 6.
Copy or print the estimate, and optionally record weight locally in this browser.
Features
Mifflin–St Jeor, revised Harris–Benedict, and optional Katch–McArdle BMR formulas
Estimated BMR, TDEE, and goal-adjusted calories
Metric and imperial height and weight inputs
Balanced, higher-protein, lower-carbohydrate, keto-style, and endurance-style presets
Custom protein, carbohydrate, and fat ratios that total 100%
Daily macro grams and calorie contribution
Even macro split for 2–6 meals as a planning aid
Transparent activity multipliers and formula labels
Low-calorie and aggressive-deficit caution messages
Browser-local weight log with up to 30 daily entries
Copy, print, and reset controls
Responsive interface with privacy and health disclaimers
Frequently Asked Questions
How does a macro calculator work?+
It estimates BMR from your measurements, multiplies by an activity factor for estimated TDEE, applies your calorie adjustment, then divides calories across your selected protein, carbohydrate, and fat percentages.
How many calories are in a gram of protein, carbs, or fat?+
For this estimate, protein and carbohydrate use about 4 kcal per gram and fat uses about 9 kcal per gram. Actual nutrition labels can vary due to fiber, sugar alcohols, rounding, and other factors.
Which BMR formula should I choose?+
Mifflin–St Jeor is the default estimate. Revised Harris–Benedict is an alternative. Katch–McArdle uses estimated lean body mass and depends on body-fat input quality. None measures your metabolism directly.
What should my protein, carbohydrate, and fat ratio be?+
There is no single ratio suitable for everyone. The presets are calculation examples; choose based on your preferences and seek a registered dietitian or clinician for individualized guidance, particularly with health conditions.
Does the calculator include a food database or meal planner?+
No. It estimates target calories and macros only. It does not scan barcodes, identify foods, or total nutrients from meals.
Is the weekly weight-change number guaranteed?+
No. It is simple energy arithmetic, not a prediction. Body weight changes are dynamic and are influenced by many factors beyond this estimate.
Is the weight log uploaded or shared?+
No. The log is stored in local browser storage on the current device. Clearing browser data removes it; it does not sync to other devices.
Can I use this during pregnancy or for a medical diet?+
No. It is a general adult educational estimator and is not intended for pregnancy, breastfeeding, minors, eating-disorder care, or medical nutrition therapy. Ask a qualified clinician or registered dietitian.
About this tool
Free Macro Calculator
Use this Macro Calculator to estimate daily calorie and macronutrient targets from age, sex-specific equation option, height, weight, activity, and goal. Choose Mifflin–St Jeor or revised Harris–Benedict, or use Katch–McArdle when you have a body-fat estimate. Select a diet-style ratio or customize protein, carbohydrate, and fat percentages; the percentages stay normalized to 100%. Results include grams per day, calories assigned to each macro, and an optional even split across meals.
What Does a Macro Calculator Estimate?
Macronutrients are protein, carbohydrate, and fat. They provide energy and support different functions in the body. This calculator estimates resting energy expenditure (BMR), applies a selected activity multiplier to estimate total daily energy expenditure (TDEE), then applies a chosen calorie adjustment. It divides that calorie target across the selected macro percentages and converts calories to approximate grams.
These calculations are starting estimates, not measured metabolism or a prescribed diet. Daily energy needs can differ due to body composition, health, medication, training, sleep, and other individual factors. Track real trends and get qualified advice when nutrition decisions affect your health.
How the BMR and TDEE Formulas Work
Mifflin–St Jeor estimates BMR from weight, height, age, and a male or female equation constant. Revised Harris–Benedict uses a different set of coefficients for the same measurements. Katch–McArdle estimates resting energy from lean body mass, calculated from weight and entered body-fat percentage. Body-fat measurements and all equations have error; the Katch option falls back to Mifflin–St Jeor unless the entered percentage is within the supported range.
TDEE is calculated by multiplying estimated BMR by the selected activity multiplier. Activity labels are broad, and the multiplier is an assumption rather than a measured activity assessment. If the estimate does not match your observed weight trend and food intake over several weeks, do not treat the displayed number as exact.
Protein, Carbohydrate, and Fat Grams
For the conversion, protein and carbohydrate are each counted as approximately four kilocalories per gram, while fat is counted as approximately nine. For example, a 2,000 kcal target with a 30% protein, 40% carbohydrate, and 30% fat split works out to about 150 g protein, 200 g carbohydrate, and 67 g fat after rounding. The calorie contribution of each macro is displayed so the math is transparent.
The preset splits are convenience options, not universal dietary recommendations. You can choose a balanced, higher-protein, lower-carbohydrate, keto-style, endurance-style, or custom ratio. Selecting a preset does not assess suitability for a medical condition, sport, or personal nutritional requirement. For a customized diet, consult a registered dietitian or qualified clinician.
Choose a Goal and Review the Estimate
Choose fat loss, maintenance, or build/gain, then set a moderate calorie adjustment. A negative adjustment lowers the estimated maintenance target; a positive adjustment raises it. The weekly change shown is simple energy arithmetic and is not a forecast. Real body-weight changes are dynamic and can differ substantially from the calculation.
The tool displays a caution when the calorie target is below 1,200 kcal per day or when the selected deficit implies a simple weekly rate above 1% of entered body weight. These are prompts to seek individualized guidance, not clinical thresholds or guarantees of safety. The calculator deliberately avoids extreme-restriction presets.
Macro Targets Per Meal and Local Weight Tracking
Choose two to six meals to see an even arithmetic division of your daily macro targets. This is only a planning convenience; meals do not need to be identical. A small weight log can record up to 30 daily entries in this browser. It does not sync across devices or upload your entries to WebToolsEdge.
This tool does not include a food database, meal planner, barcode scanner, or nutrient tracker. If you need to check a packaged food or build a meal log, consult the product label or a reliable nutrition database; this calculator only creates target estimates.
Who Should Not Rely on This Estimate?
This general adult calculator is not designed for children or teens, pregnancy or breastfeeding, eating-disorder recovery, or medical nutrition therapy. People with diabetes, kidney or liver disease, gastrointestinal conditions, a history of disordered eating, or medications that affect appetite or metabolism should seek advice from a healthcare professional or registered dietitian before changing calorie or macro intake. Seek urgent care for serious symptoms rather than using an online calculator.
How to Use the Macro Calculator
Enter adult age, height, and weight, then select the equation option and typical activity level. Choose a goal and moderate adjustment, select a macro preset or customize the sliders, and review calorie and gram totals. You can divide the estimate by meals, print or copy a summary, or optionally log weight in local browser storage. Reassess assumptions over time and treat the output as educational only.
Want to compare calorie goals without customizing macro ratios? Try the Calorie Needs Calculator. For a hydration planning estimate, see the Water Intake Calculator, or browse all Calculators. These tools provide general estimates, not individualized nutrition guidance.