Find your daily calorie target and how long it will take to reach your goal weight — based on your TDEE and chosen rate of loss.
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Daily calorie target
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kcal / day
Daily deficit
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kcal / day
Your TDEE (maintenance)
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Weight to lose
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Estimated time to goal
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Estimated goal date
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Milestones
Starting weight—
25% to goal—
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Goal weight—
Calorie Deficit Reference Guide
How different deficit sizes translate to weight loss speed and weekly calorie targets.
Daily deficit
Loss per week
Safety rating
200–300 kcal
~0.2 kg / 0.5 lb
Very safe — slow
400–600 kcal
~0.5 kg / 1 lb
✓ Recommended range
700–1,000 kcal
~0.7–1 kg / 1.5–2 lb
Caution — muscle loss risk
> 1,000 kcal
> 1 kg / 2 lb
Not recommended long-term
Frequently Asked Questions
First, find your Total Daily Energy Expenditure (TDEE) — how many calories you burn per day including all activity. Then subtract the deficit you want. This calculator does this automatically using the Mifflin–St Jeor equation. For example, if your TDEE is 2,200 kcal and you want to lose 0.5 kg/week, your daily calorie target is approximately 2,200 − 550 = 1,650 kcal.
Yes — a 500 kcal daily deficit is the most commonly recommended target for sustainable fat loss. It produces approximately 0.5 kg of weight loss per week, which is within the 0.25–0.5 kg/week range recommended by most health authorities. Beyond 1,000 kcal/day deficit, the risk of muscle loss, nutritional deficiencies, and metabolic adaptation increases significantly.
To lose 1 kg per week, you need a total weekly deficit of approximately 7,700 kcal, which equals a daily deficit of around 1,100 kcal. For most people this is aggressive and sustainable only for short periods. It works best for people with higher body weight and TDEE who can sustain a large deficit without going below ~1,200–1,500 kcal/day.
The most common reasons: underestimating calorie intake (restaurant and packaged food calories are often higher than expected), overestimating exercise calories burned, water retention masking fat loss on the scale (especially early on or around hormonal cycles), and metabolic adaptation — the body slightly reduces TDEE in response to prolonged deficit. If weight has stalled for 2–3 weeks, try reducing intake by a further 100–150 kcal or adding 20–30 minutes of walking rather than making large cuts.
This depends on how you set up your deficit. If you calculated TDEE using a moderate activity multiplier that already accounts for your exercise (e.g. 1.55), then no — exercise calories are already included. If you used a sedentary multiplier (1.2) and exercise separately, eating back 50–75% of exercise calories is a reasonable approach. Avoid eating back 100% — calorie burn estimates from wearables and machines are often 20–30% too high.
How a Calorie Deficit Works
Weight loss comes down to one core principle: consuming fewer calories than you expend. When your body is in a calorie deficit, it draws on stored energy — primarily fat — to make up the shortfall. The rate at which this happens depends on the size of the deficit and your individual metabolism.
The widely cited rule of thumb is that 1 kg of body fat contains approximately 7,700 kcal of energy. So a 550 kcal daily deficit creates a ~3,850 kcal weekly deficit, which equates to roughly 0.5 kg of fat loss per week. In practice, early weight loss may be faster due to water loss associated with glycogen depletion.
💡 The 7,700 rule is an estimate. Actual fat loss per unit of deficit varies by individual, body composition, and how long you've been dieting. Use it as a planning tool, not a guarantee.
How Big Should Your Deficit Be?
The right deficit balances speed of loss against sustainability and muscle preservation. Most research supports a deficit of 400–600 kcal per day (about 0.5 kg/week) as the sweet spot for most people:
It produces meaningful progress — roughly 2 kg per month
It is large enough to require dietary discipline but small enough to maintain long-term
It preserves muscle mass when paired with adequate protein (1.6–2.2 g/kg) and resistance training
It avoids the metabolic adaptation and fatigue that comes with very large deficits
Larger deficits (700–1,000+ kcal/day) can work for people with higher body weight, but they increase the risk of muscle loss and are harder to maintain. If you go this route, use our Macro Calculator to ensure your protein target is met, and consider diet breaks every 6–8 weeks.
What to Eat on a Calorie Deficit
The source of your calories matters almost as much as the total. To feel full and maintain muscle while in a deficit:
Prioritise protein: Aim for 1.6–2.2 g per kg of body weight. Protein is the most satiating macronutrient and essential for muscle preservation. See our high protein foods guide.
Eat high-volume, low-calorie foods: Vegetables, fruit, and lean proteins give you more food per calorie, making the deficit easier to sustain.
Keep fat intake adequate: Going below 20% of calories from fat can impair hormone function. Include avocado, olive oil, nuts, and fish.
Limit ultra-processed foods: They are calorie-dense, less satiating, and easy to overeat. They also make accurate calorie tracking harder.
Pairing Your Deficit With Exercise
Exercise accelerates fat loss and — critically — helps preserve muscle during a deficit. Even modest amounts of resistance training (2–3 sessions per week) significantly reduce the proportion of weight lost that comes from muscle versus fat. Cardio helps increase total calorie burn, but avoid using it as justification to eat significantly more — the burns are often overestimated. See our guide on the best exercises to lose weight.
⚠️ Do not go below 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision. Very low calorie intakes risk nutritional deficiencies, muscle loss, and metabolic harm. If your calculated deficit would take you below these thresholds, reduce the target rate of loss instead.
References:
Mifflin MD et al. A new predictive equation for resting energy expenditure. American Journal of Clinical Nutrition. 1990;51(2):241–247.
Hall KD et al. Quantification of the effect of energy imbalance on bodyweight. The Lancet. 2011;378(9793):826–837.
Helms ER et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes. International Journal of Sport Nutrition and Exercise Metabolism. 2014;24(2):127–138.