Calorie Deficit Calculator
How big a deficit gives the rate of loss you want.
Daily calorie target
1,850 kcal
550 kcal below maintenance
How the Calorie Deficit Calculator works
A pound of body fat stores roughly 3,500 calories, and a kilogram about 7,700. Divide the deficit you can sustain into that figure and you get a rate of loss. The arithmetic is simple; the part people underestimate is that bigger deficits do not scale linearly, because they cost muscle and adherence.
Not medical advice. This calculator gives a general estimate, not medical advice. It cannot account for your individual health, medical history, or medication. Talk to a qualified healthcare professional before acting on any result.
Frequently asked questions
How big should my calorie deficit be?
A useful rule is 0.5-1% of body weight lost per week, which for most people means a deficit of 300-750 calories a day. Leaner people should sit at the lower end; there is less fat available to mobilise, so an aggressive deficit takes the difference from muscle.
Is the 3,500 calories per pound rule accurate?
As a starting estimate, roughly. As a long-run predictor, no — it assumes your expenditure stays fixed, but a smaller body burns less, so real loss decelerates and plateaus below what the linear rule predicts. Expect to reduce intake or increase activity again after several weeks.
Why has my weight stopped falling in a deficit?
Most often intake has crept up without being noticed, or expenditure has fallen because a smaller body costs less to run and dieting quietly reduces spontaneous movement. Water retention can also mask several weeks of genuine fat loss on the scale. Track a 7-day rolling average rather than daily readings.
What is the smallest safe calorie intake?
Commonly cited floors are about 1,200 calories a day for women and 1,500 for men, below which meeting micronutrient needs becomes difficult without supervision. Very low calorie diets exist clinically but are monitored for good reason.
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