Mifflin-St Jeor · 5 activity levels · 4 diet presets
Your calorie target and macro grams in 30 seconds
Enter your sex, age, height, weight, activity level, and goal. The macro calculator recomputes your maintenance calories and your protein, carb, and fat grams as you type.
How this is calculated
10·80 + 6.25·180 − 5·30 + 5 = 1,780 kcal. Multiplied by your Moderately active factor ×1.55 gives a TDEE of 2,759 kcal. You are holding at maintenance, so your target stays at 2,759 kcal. The Balanced split (30/40/30) then divides those calories at 4 kcal/g protein, 4 kcal/g carbs, and 9 kcal/g fat.Macro and TDEE reference: multipliers, goal deltas, split ratios, and protein targets
Every calorie and gram figure on this page rests on four fixed values: the activity multiplier applied to BMR, the daily delta tied to your goal, the protein/carb/fat ratio of your chosen style, and the calories each macro carries per gram. They rarely change and are easy to lose track of, so here they all are as tables you can read a number off directly or use to sanity-check the one the calculator returned.
Activity multipliers for TDEE
TDEE is BMR times one of five activity multipliers. The right tier reflects a normal week including workouts, not a single hard day. The last column shows what each factor produces from a sample BMR of 1,600 kcal.
| Multiplier | Level | A typical week | TDEE at BMR 1,600 |
|---|---|---|---|
| 1.2 | Sedentary | Desk work, little or no exercise | 1,920 kcal |
| 1.375 | Lightly active | Light movement or 1–3 sessions | 2,200 kcal |
| 1.55 | Moderately active | 3–5 moderate sessions | 2,480 kcal |
| 1.725 | Very active | 6–7 hard sessions or a physical job | 2,760 kcal |
| 1.9 | Extra active | Twice-daily training or heavy labor | 3,040 kcal |
Goal adjustments by pace
Your goal sets a daily delta against TDEE. Cutting has three paces, gaining has two, and maintenance holds flat. The far column shows each target starting from a sample 2,400 kcal TDEE.
| Goal and pace | Daily delta | Weekly change | Target from 2,400 TDEE |
|---|---|---|---|
| Cut · mild | −250 kcal | ≈ 0.5 lb / 0.23 kg | 2,150 kcal |
| Cut · moderate | −500 kcal | ≈ 1 lb / 0.45 kg | 1,900 kcal |
| Cut · aggressive | −750 kcal | ≈ 1.5 lb / 0.68 kg | 1,650 kcal |
| Maintain | 0 kcal | Hold | 2,400 kcal |
| Gain · mild | +250 kcal | ≈ 0.5 lb / 0.23 kg | 2,650 kcal |
| Gain · moderate | +500 kcal | ≈ 1 lb / 0.45 kg | 2,900 kcal |
A cut is the only direction with a guardrail: if the delta would push the target below 1,200 kcal, the calculator holds it at 1,200. Surplus and maintenance targets are never floored.
Dietary-style splits in grams
Each style is a fixed protein/carb/fat percentage applied to the calorie target. The grams below are worked at a 2,000 kcal target, using 4 kcal/g for protein and carbs and 9 kcal/g for fat.
| Style | P / C / F split | Protein | Carbs | Fat |
|---|---|---|---|---|
| Balanced | 30 / 40 / 30 | 150 g | 200 g | 67 g |
| High-protein | 40 / 35 / 25 | 200 g | 175 g | 56 g |
| Low-carb | 40 / 20 / 40 | 200 g | 100 g | 89 g |
| Keto | 25 / 5 / 70 | 125 g | 25 g | 156 g |
To scale any row to your own target, the grams follow one rule:
Macro constants and protein targets
The building blocks the engine reuses on every recalculation: the energy each macro carries, the Mifflin-St Jeor terms, and a protein-gram lookup so you can check your protein tile against a per-kilogram floor.
Energy per gram
| Macro | Energy | Note |
|---|---|---|
| Protein | 4 kcal/g | Same density as carbs |
| Carbohydrate | 4 kcal/g | Fiber counts here too |
| Fat | 9 kcal/g | Densest of the three |
| Alcohol | 7 kcal/g | Not a tracked macro, listed for context |
Mifflin-St Jeor terms
BMR sums these four terms: BMR = 10·kg + 6.25·cm − 5·age + sex constant.
| Term | Contribution | Applies to |
|---|---|---|
| Weight | +10 per kg | Everyone |
| Height | +6.25 per cm | Everyone |
| Age | −5 per year | Everyone |
| Sex constant | +5 men · −161 women | Sex-specific offset |
Protein target by bodyweight
Protein is the macro to read in grams, not percent. A common working floor is 1.6 g/kg; 2.0 and 2.2 g/kg suit an active cut.
| Bodyweight | 1.6 g/kg | 2.0 g/kg | 2.2 g/kg |
|---|---|---|---|
| 50 kg / 110 lb | 80 g | 100 g | 110 g |
| 60 kg / 132 lb | 96 g | 120 g | 132 g |
| 70 kg / 154 lb | 112 g | 140 g | 154 g |
| 80 kg / 176 lb | 128 g | 160 g | 176 g |
| 90 kg / 198 lb | 144 g | 180 g | 198 g |
| 100 kg / 220 lb | 160 g | 200 g | 220 g |
| 110 kg / 243 lb | 176 g | 220 g | 242 g |
Related concepts
- Basal metabolic rate (BMR): resting energy before any activity is added.
- Total daily energy expenditure (TDEE): BMR scaled by the activity multiplier.
- Harris-Benedict equation: the older BMR formula Mifflin-St Jeor was built to improve on.
- Katch-McArdle formula: a lean-mass-based BMR path for people who know their body-fat percentage.
- Largest-remainder rounding: the method that keeps the three split percentages summing to exactly 100.