Calculators guide
How Big Should Your Calorie Deficit Be? Picking a Pace
· 4 min read
For most adults, a deficit of roughly 275 to 550 kcal a day below maintenance is a sensible place to start. That works out to about 0.25 to 0.5 kg (roughly half a pound to a pound) of weight loss per week. Larger deficits are possible on paper, but they can quickly run into minimum intake levels and become hard to keep up. Whatever the numbers say, treat them as an estimate to adjust over time, not as medical advice.
Where does the deficit come from?
A calorie target starts with your maintenance level, or TDEE: the estimated energy you use on a normal day. The Calorie Calculator estimates it in two steps:
- Basal metabolic rate (BMR) from the Mifflin-St Jeor equation, using sex, age, weight and height.
- BMR multiplied by an activity factor, from 1.2 (sedentary) to 1.9 (very active).
Then it adjusts for your goal using a common rule of thumb: a kilogram of body fat holds about 7,700 kcal. Spread over seven days, each goal becomes a daily adjustment:
| Goal | Daily change |
|---|---|
| Lose 1 kg per week (aggressive) | −1,100 kcal |
| Lose 0.5 kg per week | −550 kcal |
| Lose 0.25 kg per week | −275 kcal |
| Maintain weight | 0 |
| Gain 0.25 kg per week | +275 kcal |
| Gain 0.5 kg per week | +550 kcal |
If you want the background on BMR and activity factors themselves, the BMR Calculator covers that part on its own.
Comparing the options with real numbers
Take a 32-year-old woman who weighs 70 kg, is 170 cm tall and exercises lightly. Her estimated BMR is 1,442 kcal and her maintenance is about 1,982 kcal a day.
| Goal | Daily target |
|---|---|
| Lose 0.25 kg/week | 1,707 kcal |
| Lose 0.5 kg/week | 1,432 kcal |
| Lose 1 kg/week | 1,200 kcal (see below) |
Now a 40-year-old man, 85 kg, 180 cm, moderately active. His estimated maintenance is about 2,759 kcal:
| Goal | Daily target |
|---|---|
| Lose 0.5 kg/week | 2,209 kcal |
| Lose 1 kg/week | 1,659 kcal |
The same goal costs both of them the same number of calories per day, but it's a much bigger share of her budget than of his. That's the main reason one fixed pace doesn't suit everyone.
Why did the target stop at 1,200?
For the woman above, the aggressive goal works out to 1,982 − 1,100 = 882 kcal. The calculator doesn't go that low. It raises weight-loss targets to at least 1,200 kcal a day for women and 1,500 kcal for men, which are commonly used minimums without medical supervision, and shows a note when it does.
When you see that note, the real pace will be slower than the goal you chose. In this case, eating 1,200 kcal is a deficit of about 782 kcal, or roughly 0.7 kg a week, not 1 kg.
How to choose a pace
- 0.25 kg/week suits people close to their goal weight, people who train hard, or anyone who wants changes that barely affect daily life.
- 0.5 kg/week is a common middle ground: noticeable progress and a deficit most people can live with.
- 1 kg/week only makes sense for larger bodies with high maintenance needs. For many people, the floor kicks in before the full deficit does.
- Gain goals are mainly for building muscle alongside strength training. A small surplus (+275 kcal) limits how much of the gain is fat.
Which macro split should you pick?
The calculator divides your target into grams using one of three splits. Protein and carbohydrates have about 4 kcal per gram and fat about 9, so for a 1,432 kcal target:
| Split (protein / carbs / fat) | Protein | Carbs | Fat |
|---|---|---|---|
| Balanced (30 / 40 / 30) | 107 g | 143 g | 48 g |
| Lower carb (35 / 25 / 40) | 125 g | 90 g | 64 g |
| Higher carb (20 / 55 / 25) | 72 g | 197 g | 40 g |
There's no single best split for weight loss. What matters most is the total calories and whether you can stick with the plan. Pick the one that looks like food you actually enjoy. Higher protein can help you feel full and protect muscle while you're in a deficit, which is why the balanced and lower-carb options lean that way.
Step by step in the calculator
- Choose Sex, then enter Age (years), Weight (kg) and Height (cm). If you use pounds, convert with the Weight Converter first.
- Pick your Activity level.
- Choose a Goal and a Macro split.
- Read the Daily calorie target, then Maintenance (TDEE), BMR, and grams of Protein, Carbohydrates and Fat.
The calculation runs in your browser, so your measurements aren't sent anywhere.
Adjusting after a few weeks
Equations can be off by around 10% for an individual. Weigh yourself under the same conditions several times a week and compare weekly averages. If the trend after three or four weeks is slower or faster than expected, change your intake by 100 to 200 kcal and recheck. Recalculate whenever your weight changes by a few kilograms, since maintenance falls as you lose weight.
If you're pregnant or breastfeeding, under 18, managing a medical condition, or have a history of disordered eating, talk to a doctor or registered dietitian before setting a deficit.
FAQ
Should I eat back the calories from exercise?
Not if your activity level already includes your workouts. Adding tracker calories on top counts the same exercise twice.
Are the gram targets exact?
No. They're rounded estimates. Landing within about 10 grams of each is plenty.
Find your own starting point with the Calorie Calculator.