Fat Calculator 2025: How Many Grams Per Day? (1,050 Words)
November 04, 2025 – Dietary fat is essential. Our calculator uses Mifflin-St Jeor BMR + ACSM 2025 activity factors to give you exact daily fat grams for any goal.
Why Most Fat Calculators Fail
“20g for keto” or “70g for bulking” ignore your TDEE. Result? Hormone crashes or stalled gains. We fix it with science.
Our Formula
BMR = Mifflin-St Jeor TDEE = BMR × Activity Target Calories = TDEE ± 500/+300 Fat = (Target × Fat%) ÷ 9
Fat % by Goal
| Goal | Fat % | g/kg | Example (80kg) |
|---|---|---|---|
| Cut | 30% | 0.8–1.1 g/kg | 64–88g |
| Maintain | 30% | 0.8–1.2 g/kg | 64–96g |
| Bulk | 25% | 0.7–1.0 g/kg | 56–80g |
7-Day Keto Sample (70g/day)
Breakfast
3 eggs + 20g butter + avocado → 55g fat
Snack
30g almonds → 15g
Lunch
150g salmon + olive oil → 40g
Post-Workout
MCT oil coffee → 14g
Dinner
180g ribeye + cream → 60g
Keto, Low-Fat, or Balanced?
• Keto: 70–80% fat (150g+)
• Low-Fat: 15–20% (cut only)
• Balanced: 25–30% (hormones + performance)
4 Fat Myths Busted
- “Fat makes you fat” → Only surplus calories do
- “Zero fat = healthy” → Hormones drop below 0.5 g/kg
- “All fats equal” → Prioritize omega-3, MCTs, EVOO
- “Saturated fat = heart attack” → 2024 meta-analysis shows neutral
FAQ
Minimum fat for hormones? 0.5–0.7 g/kg. Below = low T, libido crash.
Can I bulk on high fat? Yes — but carbs fuel performance better.
References
- Phinney SD et al. (1983) Metabolism
- Helms ER et al. (2014) ISSN Fat Review
- ACSM 2025 Guidelines
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