Fat intake
The useful number here is the minimum. Fat is the one macro where going too low has a real cost, and almost no calculator will tell you where that floor is.
56g
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- The standard 20–35% band
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- Do not go below
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- Grams per kg
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- Saturated fat, cap at 10%
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- Stricter cap, 7% and 6%
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- NHS saturated limit
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- Linoleic acid (omega-6)
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- Alpha-linolenic (omega-3)
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Total grams say nothing about the split between saturated, mono-, poly- and trans fat — and that split matters at least as much as the total.
How much fat: 20 to 35 per cent of your calories
That is the accepted range, agreed across the US dietary reference intakes and EFSA, with the WHO preferring the lower half of it. On 2,000 calories it comes to roughly 44 to 78 grams — which is a wide enough band that "how many grams of fat a day" does not really have a single answer. This page starts at 25%.
The minimum, and why going very low backfires
This is the number worth having and the one almost nobody prints. Below the greater of 20% of your calories or half a gram per kilogram of bodyweight, you start running into real problems rather than theoretical ones.
Vitamins A, D, E and K are fat-soluble: without fat in the meal you absorb less of them. Linoleic and alpha-linolenic acid cannot be made by the body at all and have to arrive in food. And in sport specifically, intakes at or under 20% of energy show no performance benefit, so there is nothing being bought with the cut.
The trap is a percentage applied to a small calorie target. Twenty-five per cent of 1,200 calories is 33 grams, which for a heavier person is under the floor — a percentage alone cannot see that, which is why this page checks against grams per kilogram too.
Saturated fat: 10%, 7% or 6%?
All three are real, which is why the advice feels contradictory. The WHO sets under 10% of energy as the general limit. Seven per cent is the figure used where reducing heart-disease risk is the goal. The American Heart Association goes further, to 6% — about 13 grams on a 2,000 calorie diet. The NHS skips percentages and gives grams outright: no more than 30 a day for men, 20 for women. All of them are shown above so you can see the spread rather than wonder which one applies.
Trans fat has no useful threshold — the WHO target is under 1% of energy and the practical answer is as little as possible.
The omegas are the reason fat is essential
Linoleic acid and alpha-linolenic acid are the two your body cannot synthesise. The adequate intakes are around 17 g and 1.6 g a day for men, and 12 g and 1.1 g for women. These are small numbers that come easily from nuts, seeds, oily fish and vegetable oils — and they are the specific reason a very low fat intake is a problem rather than merely unpleasant.
Fat on a low-carb or keto diet
On a ketogenic diet, fat takes 60 to 80 per cent of energy because carbohydrate has been fixed low and protein is set from bodyweight — fat is simply what is left. That is a deliberate therapeutic pattern, not a general recommendation, and it changes which of the caps above you should be watching. Thecarb calculator handles the other side of it.
Where to be careful
If you have cardiovascular disease, raised LDL cholesterol, familial hypercholesterolaemia, or take a statin, your saturated fat target should come from your clinical team and may well be stricter than any figure here. Gallbladder disease, pancreatitis and fat-malabsorption conditions all need clinician-set intakes, sometimes in the other direction. General information, not medical advice.