How many calories are in a biscuit?
A plain digestive is about 70 kcal. A chocolate digestive is about 85, a rich tea 38, a custard cream 62, and a bakery chocolate chip cookie 250–280. The per-biscuit number is small, which is precisely the difficulty: nothing about eating one is a decision.
Per portion
| Portion | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| One rich tea (8 g) | ~38 kcal | 0.5 g | 6 g | 1.2 g |
| One digestive (15 g) | ~70 kcal | 1 g | 10 g | 3 g |
| One chocolate digestive (17 g) | ~85 kcal | 1.1 g | 11 g | 4 g |
| One custard cream (13 g) | ~62 kcal | 0.7 g | 9 g | 2.8 g |
| One bourbon (13 g) | ~65 kcal | 0.8 g | 9 g | 2.8 g |
| One shortbread finger (20 g) | ~100 kcal | 1 g | 12 g | 5.5 g |
| Bakery chocolate chip cookie (55 g) | ~260 kcal | 3 g | 34 g | 12 g |
| 100 g, about six digestives | ~480 kcal | 6.5 g | 64 g | 21 g |
What changes the number
Fat, not sugar, explains the spread. Biscuits run 450–540 kcal per 100 g, and the difference between those ends is mostly butter or palm oil. Rich tea and ginger nuts are the lean end at 450–460. Shortbread, with roughly twice the fat, is 520–540.
Coatings and creams. A chocolate coating on one side adds about 15 kcal; a cream filling 15–25; fully enrobed, 25–35 — which also means a chocolate biscuit is not double a plain one.
Size, which dwarfs everything else. An own-brand digestive and a café cookie are both “a biscuit” at 70 and 260 kcal. Bakery cookies weigh 50–80 g and reach 400 kcal when stuffed.
Labels that sound dietary. “Digestive” is a Victorian name and means nothing nutritionally. Oat, wholemeal and seeded versions carry a little more fibre and identical calories. Reduced-fat ranges are a genuine 15–25% lower, though usually smaller too.
Where it fits in a deficit
Under 1 g of protein, under 1 g of fibre and almost no water means satiety per calorie is close to the floor, and the texture is built for speed. Two hundred kcal of biscuits leaves appetite roughly where it started, whereas 200 kcal of protein does not.
That is an argument about where biscuits work, not whether they are allowed. Two with afternoon tea at 140 kcal, decided in advance, is something any plan absorbs. The open pack within reach is the part that does not work, and the fix is logistical: the small pack, or four on a plate with the roll back in the cupboard. A doughnut or a bar of chocolate at least announces itself; biscuits do not.
Three a day, for a year
No lecture, just the arithmetic, which is rarely done:
- Three digestives a day is about 210 kcal.
- A week is roughly 1,470 kcal, two-thirds of a day’s food for most people.
- A year is about 77,000 kcal, or roughly 10 kg (22 lb) at the 7,700 kcal per kilogram of body fat used for these sums.
- A 400 g pack is around 1,900 kcal: at three a day, a pack every nine days.
The real figure is smaller than 10 kg: appetite partly compensates, intake is never that consistent, and nobody eats the same three biscuits for 365 days. Treat it as a sense of scale, not a prediction. The reliable part is the daily number: 210 kcal has to come from somewhere, a tenth of a 2,000 kcal day, the size of a modest calorie deficit by itself. Three biscuits are also, for some people, what makes the afternoon work — a perfectly good reason to spend 210 kcal, as long as it is spent knowingly rather than absently.
Figures are typical values and vary by variety, size and preparation. General information, not medical advice.