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Sex
Height
Weight
Current weight
Goal weight

How the numbers are worked out

Everything starts with your Basal Metabolic Rate (BMR) — the amount of energy you burn at complete rest. The Harris–Benedict equation estimates it using your sex and age together with your height and current weight, and multiplying by your activity level gives your maintenance calories — the intake that holds your weight where it is.

From goal date to daily target

A kilogram of body weight equates to about 7,700 kcal. Given the change you're after and the weeks available before your goal date, the tool calculates the daily calorie deficit (or surplus) involved, then adjusts your maintenance calories by that amount to set your daily target.

Safe limits matter

Shedding upwards of 1 kg in a week, or eating below a daily floor of roughly 1,200 kcal for women — 1,500 for men — generally isn't recommended. The calculator warns you if your goal date would push past those boundaries — extending your timeline is usually the wiser move. None of this replaces personalised medical advice.