How many calories are in butter?
A level teaspoon of butter (5 g) is about 36 kcal. A tablespoon (14 g) is about 100 kcal, and 100 g is roughly 715 kcal. Butter is around 80% fat and 16% water with almost no protein or carbohydrate, so the calorie figure tracks weight almost perfectly — which is exactly the problem, because butter is one of the few foods nobody ever weighs.
Per portion
| Portion | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| 1 level teaspoon, or a thin scrape (5 g) | ~36 kcal | 0 g | 0 g | 4 g |
| 1 tablespoon (14 g) | ~100 kcal | 0.1 g | 0 g | 11.5 g |
| Single wrapped pat (7–10 g) | ~50–70 kcal | 0.1 g | 0 g | 6–8 g |
| Generous spread on one slice (15 g) | ~110 kcal | 0.1 g | 0 g | 12 g |
| A knob for the pan (20 g) | ~145 kcal | 0.2 g | 0 g | 16 g |
| 100 g (about 7 tablespoons) | ~715 kcal | 0.9 g | trace | 81 g |
What changes the number
How thickly you spread it. This is most of the story. A thin scrape is 4–6 g, a normal buttering is 8–12 g, and a properly buttered slice of fresh bread is 15–20 g. Same bread, same knife, same person: 36 kcal to 145 kcal. No other variable on this page comes close.
Butter in the pan. Cooking fat does not burn off. A fried egg cooked in 10 g of butter keeps most of it, and a pan of vegetables sautéed in 20 g has absorbed 145 kcal the vegetables did not have before. Butter sits near the top of the calorie density ladder, so it changes a dish’s total faster than the dish itself does.
Salted or unsalted. No meaningful difference. Salt is 1–2% of the weight.
Spreads and blends. Butter blended with rapeseed or olive oil runs roughly 550–650 kcal per 100 g; light and reduced-fat spreads about 380–540 kcal. Those are real reductions per gram, but softer spreads also go on thicker, which eats some of the saving. Reading the per-100 g column is worth more here than the claim on the front of the tub.
Clarifying it. Removing the water concentrates the fat, so ghee is higher per gram than butter, not lower.
Where it fits in a deficit
Butter is nearly pure fat at 9 kcal per gram, with no protein, no fibre and no volume, so it contributes nothing to fullness per calorie. That does not make it a food to avoid. Ten grams of butter on 300 g of green beans is 72 kcal and often decides whether the beans get eaten at all, which is good value.
The trouble is never the deliberate 10 g. It is the three or four undeliberate portions a day that were each assumed to be a teaspoon. If something is going on toast most mornings, peanut butter is a slightly cheaper option per gram and brings protein and fibre with it.
The measurement problem
Invisible fats — butter, oil, dressing, mayonnaise — are where food diaries quietly fall apart, because they go on in the gaps between the things you remember eating. Butter is the worst offender because the units people use for it are adjectives: a scrape, a bit, a knob.
Weigh it once. Put the butter dish on a kitchen scale, zero it, butter your toast the way you actually do, and weigh the dish again. If the honest answer is 15 g and you have been assuming 5 g, two slices a day is around 145 kcal unaccounted for — enough on its own to flatten a modest calorie deficit.
After that you do not need the scale, just one of three habits: a measured teaspoon, butter soft enough that a thin layer actually spreads, or a block pre-cut into 10 g slabs. Any of them replaces an adjective with a number.
Figures are typical values and vary by variety, size and preparation. General information, not medical advice.