How to use this calculator
- Enter or choose daily calories.
- The total fat (20–35% of energy) updates as you type. Use Copy result or Share to keep it.
Method
Fat (g) = Calories × share ÷ 9; total fat 20–35% (AMDR), ≤ 30% (WHO); saturated ≤ 10%; trans ≤ 1%
- Calories
- daily energy intake in kcal
- share
- the guideline percentage as a fraction
- 9
- kcal per gram of fat
Worked example
- 20% of 2,000 = 400 kcal ÷ 9 = 44 g; 35% = 700 kcal ÷ 9 = 78 g.
- WHO 30%: 600 ÷ 9 = 67 g.
- Saturated fat 10%: 200 ÷ 9 = 22 g; trans fat 1%: 20 ÷ 9 = 2.2 g.
On 2,000 kcal a day, total fat of about 44–78 g fits the AMDR, with no more than 22 g of saturated fat.
What the result means
The type of fat matters more than the total: guidelines favour replacing saturated and trans fats with unsaturated fats from foods such as fish, nuts, seeds and vegetable oils.
Assumptions and limits
- Guidelines are for healthy adults: the AMDR of 20–35% (US/Canada Dietary Reference Intakes) and the WHO 2023 guideline on fats.
- Fat provides 9 kcal per gram.
- Children, pregnancy and medical diets (for example for pancreatitis or high triglycerides) have different targets.
- Food labels round fat content, so tracked totals are approximate.
Questions
Why do the AMDR and WHO figures differ?
The AMDR range (20–35%) is the band associated with adequate nutrition and lower chronic-disease risk in US/Canada reviews; WHO advises adults keep total fat at 30% or less. Both set saturated fat near 10% or below.
Is low-fat always better?
Not necessarily. Below about 20% of energy it becomes harder to get essential fatty acids and fat-soluble vitamins, and low-fat foods are often higher in refined carbohydrate.
Sources
Please note: This is a general screening estimate for adults, not medical advice or a diagnosis. Talk to a qualified health professional about your health.