AIFitLog Tools

Macro Calculator
Hit Your Numbers. Every Day.

Enter your TDEE and body weight to get your daily protein, fat, and carb targets.
Pick a diet style — or go fully custom. Free, no signup.

Step 1 — Your Numbers

Unit

Maintenance Calories (TDEE)

kcal

Body Weight

Auto-filled from your TDEE calculator

Don't know your TDEE? Calculate it here

Step 2 — Monthly Goal (optional)

Bulk (+) or Cut (−) per month

lb / mo

⚠️

Target Calories

—

kcal / day

Step 3 — Diet Style

Protein

Fat

Carbs

Enter values for P, F, and C — they must add up to 100%.

Enter your TDEE above to see your macros

Track macros smarter —
let AI do the analysis

AIFitLog logs your meals and workouts, then gives you AI-powered insights
on whether your nutrition is actually moving you toward your goal.

Available in English and Japanese

About This Calculator

Macros (macronutrients) are the three nutrients your body uses for energy: protein, fat, and carbohydrates. Even at the same calorie target, the ratio between them significantly affects body composition — how much muscle you build or preserve, and how much fat you gain or lose.

Diet style ratios used here: Balanced (P25%/F25%/C50%) is a solid general-purpose starting point. Ketogenic (P20%/F75%/C5%) cuts carbs to near-zero, forcing your body to run on fat via ketosis. Low-Carb (P30%/F40%/C30%) reduces carbs moderately — a practical choice for many dieters. Low-Fat (P35%/F20%/C45%) keeps dietary fat minimal while maintaining carb intake. Custom lets you set any ratio you want.

How to use it: Get your TDEE from the TDEE Calculator, enter your body weight, optionally set a monthly goal, then pick a diet style. Your gram targets update instantly.

Frequently Asked Questions

How much protein do I actually need?

For muscle retention and growth, 0.73g per pound (1.6g/kg) of body weight per day is the most well-supported minimum, based on multiple meta-analyses including Morton et al. (2018). A 165 lb person would aim for roughly 120g/day. This floor becomes especially critical when cutting — protein preserves muscle during a deficit. During a lean bulk, going up to 1.0g/lb (2.2g/kg) may offer marginal additional benefit, though research shows diminishing returns above 0.73g/lb.

What's the difference between keto and low-carb?

Low-carb simply reduces carbohydrate intake — typically to 20–30% of calories — without a strict threshold. Ketogenic goes much further, cutting carbs to around 5% of calories (roughly 20–50g/day), with the specific goal of entering ketosis: a metabolic state where your body burns fat for fuel instead of glucose. Keto requires more discipline and consistent tracking. Starting with the low-carb preset before attempting keto is a practical first step.

Where do I get my calorie number (TDEE)?

Use the TDEE Calculator on this site. It estimates your Total Daily Energy Expenditure from your height, weight, age, and activity level using the Mifflin-St Jeor formula — currently considered the most accurate widely-used method. Once you have it, use the cut, maintain, or bulk targets it generates as your input here.

Can I set my own macro split?

Yes — select Custom and enter any percentages you want. As you fill in values, the remaining percentage is shown so you can easily hit 100%. Useful if you follow IIFYM, have targets from a nutritionist, or just want to try a specific split.

How is the monthly goal converted to calories?

One pound of body fat contains roughly 3,500 kcal. To lose or gain that pound over 30 days, you need a daily deficit or surplus of about 117 kcal. This calculator multiplies your monthly goal by 3,500 and divides by 30 to get your daily calorie adjustment from TDEE.

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Track macros smarter —let AI do the analysis

Track macros smarter —
let AI do the analysis