How long does it take to lose 10 kg (22 lb)?

Losing 10 kg (22 lb) at a healthy rate of 0.5 kg (1 lb) per week takes about 20 weeks, or roughly five months. But the 7,700 kcal-per-kg rule is a simplification, and most people find the pace slows as they get lighter — both because there is less body to carry and because metabolism adapts to a sustained deficit.

Why the 7,700 kcal rule is a starting point, not a deadline

The number comes from the energy content of adipose tissue, roughly 7,700 kcal per kilogram. A 500 kcal daily deficit adds up to about 3,500 kcal a week, or roughly 0.45 kg, close to the 0.5 kg per week used in the table below.

The rule treats your deficit as fixed, but it isn't. As you lose weight your body needs less energy, so the same food intake produces a smaller deficit over time. Dynamic models show that the simple rule therefore overestimates how much weight is lost over months, even though it works reasonably well for the first few weeks. Early scale changes also include water and glycogen, so the first weeks can look faster than fat loss alone.

Why weight loss slows over time

Your energy needs fall. A 60 kg body needs fewer calories than a 70 kg one, so if you keep eating the same amount, your deficit shrinks as you lose. Recalculate every few kilograms.

Adaptation can add to this. Some studies find resting energy expenditure falls more than weight loss alone predicts. The size of the effect varies between people and is still debated.

Plan for the pace to slow, and recalculate along the way, instead of expecting a straight line.

Timeline for losing 10 kg at different rates
Rate	Time for 10 kg	Notes
0.25 kg/week	~40 weeks	Very gentle; easier to sustain
0.5 kg/week	~20 weeks	Standard recommendation
0.75 kg/week	~14 weeks	Aggressive; harder to maintain
1.0 kg/week	~10 weeks	Upper end of the commonly cited range; harder to sustain

Timelines assume a person with 10 kg to lose safely and are not for people at a healthy or low weight, under 18 or pregnant.

When progress stalls

Daily weight swings with water, so judge progress on a 2 to 3 week average before changing anything. If the average has really stopped, recheck your tracking, reduce intake by 100 to 200 kcal, or add activity. Planned breaks at maintenance are popular, but the evidence that they "reset hormones" is weak, and the main benefit is probably that they make the plan easier to stick to.

Formulas are estimates, not medical advice.

Sources

National Health Service. How to lose weight. NHS Health Check.
Used for: Safe, gradual rate-of-weight-change framing, and the 0.5-1 kg per week range most guidance supports.
Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247.
Used for: Basal metabolic rate from weight, height, age and sex — the foundation of the TDEE and calorie-target calculators.
Hall KD, Sacks G, Chandramohan D, Chow CC, Wang YC, Gortmaker SL, Swinburn BA. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837.
Used for: Background on why the 7,700 kcal/kg adipose energy value overstates long-term weight-loss expectations.
Camps SG, Verhoef SP, Westerterp KR. Weight loss, weight maintenance, and adaptive thermogenesis. Am J Clin Nutr. 2013;97(5):990-994.
Used for: Evidence that sustained calorie restriction lowers resting energy expenditure beyond what body-weight loss alone explains.

For how to size that deficit and why a moderate gap usually beats an extreme one, read the calorie-deficit-size guide. For how tracking works once you start, see the TDEE tracking guide.

Use the calculator

Enter your weight, height, age, sex and activity level into the calorie deficit calculatorto get a daily target based on a rate of loss you choose. It uses the 7,700 kcal-per-kg constant to convert your weekly goal into a daily number, and it will pause if the target drops below a safe minimum.