What Is a Good Calorie Deficit for Weight Loss?
"Just eat less" is technically correct and completely unhelpful. The real question is how much less — too small a deficit and weight loss stalls, too large and you risk muscle loss, fatigue, and giving up altogether. Here's how to work out a calorie deficit that's actually sized right for you.
Contents
How a Calorie Deficit Works
A calorie deficit simply means eating fewer calories than your body burns in a day — that daily burn figure is your TDEE (total daily energy expenditure), covering your basal metabolic rate plus activity. Run a consistent deficit and your body draws on stored energy, mostly body fat, to cover the shortfall, which is the basic mechanism behind essentially all weight loss, regardless of diet style or macro split.
Deficit Size: Small, Moderate and Large
There's no single "correct" deficit — the right size depends on how much weight you have to lose, how aggressively you want to lose it, and how sustainable you need the plan to be. Broadly, deficits fall into three bands:
| Deficit Size | Daily Deficit | Approx. Weekly Loss | Best Suited To |
|---|---|---|---|
| Small | 250-300 cal | ~0.25kg | Those close to goal weight, prioritising muscle retention and sustainability |
| Moderate | ~500 cal | ~0.5kg | Most people — a well-studied, widely recommended starting point |
| Large | 750-1000 cal | ~0.75-1kg | Higher starting bodyweight, shorter planned duration, ideally with guidance |
🧮 Calculate Your Daily Target
Work out your exact calorie deficit target and estimated weekly loss rate.
Open Calorie Deficit Calculator →How to Calculate Your Own Deficit
Start from your TDEE — your maintenance calories, the amount that keeps your weight stable — then subtract your chosen deficit size.
Worked Example
A generic online TDEE estimate can be off by several hundred calories for an individual, since it doesn't account for your actual activity level, body composition, or metabolic rate — a proper TDEE calculator that factors in age, sex, weight, height and activity level gets you much closer to an accurate starting number.
Why Bigger Isn't Always Faster
It's tempting to assume a 1000-calorie deficit loses weight twice as fast as a 500-calorie one — in practice it's rarely that clean. Larger deficits tend to come with real trade-offs:
- More muscle loss — a severe deficit increases the share of weight lost from lean tissue rather than fat, especially without adequate protein and resistance training.
- Metabolic adaptation — the body partially compensates for a large, sustained deficit by lowering its energy expenditure (adaptive thermogenesis), narrowing the actual gap over time.
- Harder adherence — more hunger, fatigue and irritability make a steep deficit much harder to sustain for more than a few weeks, which often leads to abandoning the plan entirely.
- Higher rebound risk — rapid, aggressive weight loss is more strongly associated with regaining the weight afterward compared with slower, steadier loss.
When the Scale Doesn't Move
A genuine calorie deficit doesn't always show up on the scale day to day. Water retention from sodium, carbohydrate intake, menstrual cycle, stress, and even recent exercise can swing daily weight by a kilogram or more in either direction, easily masking real fat loss for a week or longer. Tracking a 7-day rolling average rather than single daily readings, and being honest about logging accuracy (restaurant meals, oils, drinks, and bites of other people's food all add up), resolves most apparent "stalls."
Summary
A good calorie deficit for weight loss is one you can actually sustain — typically 250-750 calories per day below your TDEE, depending on how much weight you want to lose and how quickly. Calculate your target from an accurate TDEE rather than a generic estimate, and be wary of very large deficits that trade short-term speed for muscle loss and poor adherence.
This article provides general health and fitness information only and is not a substitute for personalised advice from a doctor or accredited dietitian.
Frequently Asked Questions
What is a good calorie deficit for weight loss?
A deficit of roughly 500 calories per day below your maintenance (TDEE) is a commonly used starting point, producing an estimated loss of around 0.5kg per week. A more moderate deficit of 250-300 calories per day is often more sustainable for people with less weight to lose or who struggle with hunger, while a larger deficit of up to 750-1000 calories can suit those with more weight to lose, for a shorter period, under appropriate guidance.
Is a 1000 calorie deficit too much?
For many people, a 1000-calorie daily deficit is aggressive and hard to sustain, and can increase muscle loss, fatigue, and the likelihood of regaining weight afterward. It may be appropriate short-term for people with a higher starting bodyweight and under professional guidance, but it is not a universal recommendation.
How do I calculate my calorie deficit for weight loss?
Start with your TDEE (total daily energy expenditure, your maintenance calories), then subtract your target deficit. For example, a TDEE of 2200 calories minus a 500-calorie deficit gives a daily target of 1700 calories. A TDEE calculator that accounts for your age, sex, weight, height and activity level gives a more accurate starting figure than generic online estimates.
Why does the scale not move even in a calorie deficit?
Water retention, hormonal fluctuations, undigested food, and natural day-to-day weight variation can all mask fat loss on the scale for days or even a couple of weeks at a time, even in a genuine deficit. Tracking a weekly average rather than single daily readings, and being honest about tracking accuracy, usually explains an apparent stall.
Does a bigger calorie deficit mean faster fat loss?
Only up to a point. Very large deficits increase the share of weight lost from muscle rather than fat, tend to slow metabolism more through adaptive thermogenesis, and are harder to sustain consistently — all of which can make aggressive deficits slower or less effective at genuine fat loss than a moderate, consistent one over time.