This article is for general information and is not medical advice. For personalised guidance, talk to a doctor or registered dietitian.
"How many calories should I eat to lose weight?" is the single most common question in fitness — and the answer is simpler than the internet makes it sound. Fat loss comes down to one thing: a calorie deficit, eating slightly less energy than your body burns. Everything else is detail.
This guide shows you how to estimate your calories, set a sensible deficit, and avoid the mistakes that stall most people — without obsessing over every gram.
The only rule that matters: calorie balance
Your body burns a certain number of calories each day (your "maintenance" level). Eat fewer than that and your body makes up the difference by burning stored fat. Eat more and you store the excess. That's it — every diet that works, from keto to fasting, works because it helps you eat fewer calories overall.
So the real questions are: what's my maintenance level, and how big a deficit should I run?
Step 1: Estimate your maintenance calories
A quick, rough estimate of the calories you burn per day:
- Lightly active: bodyweight in pounds × 14–15
- Moderately active: bodyweight in pounds × 16
- Very active: bodyweight in pounds × 17–18
(Example: a 170 lb moderately active person ≈ 170 × 16 ≈ 2,720 calories/day to maintain.)
This is an estimate, not gospel — real maintenance depends on age, sex, muscle mass, and activity. You'll refine it using the scale over a few weeks.
Step 2: Set your deficit
Subtract from maintenance to lose fat. A moderate, sustainable deficit is best:
- Gentle:
250 calories below maintenance → slow, easy fat loss (0.5 lb/week). - Moderate (recommended): ~500 calories below maintenance → about 1 lb/week for many people.
- Aggressive: ~750–1,000 below → faster, but harder to sustain and risks losing muscle.
A common rule of thumb: aim to lose roughly 0.5–1% of your bodyweight per week. Faster than that and you'll likely feel awful, lose muscle, and rebound.
Don't go too low. Very low intakes (below roughly 1,200 for women or 1,500 for men, as a general floor) are hard to sustain, leave you hungry and depleted, and often backfire. Slower and steadier wins.
Step 3: Track, then adjust with the scale
Calculators only estimate. Your body gives you the real answer:
- Eat at your target for 2–3 weeks, tracking food honestly (a free app makes this easy).
- Weigh yourself a few mornings a week and take the weekly average (daily weight swings are mostly water).
- If the average isn't dropping, lower intake by ~150–250 calories or add activity. If you're losing too fast or feeling terrible, eat a bit more.
Adjusting based on real results beats trusting any formula.
Protein, not just calories
Calories decide whether you lose weight; protein decides whether you lose fat or muscle. Eating enough protein in a deficit protects your muscle, keeps you fuller, and improves how your body looks at the end. Aim for a high-protein diet while cutting — see how much protein you really need.
Fill the rest of your plate with vegetables, some quality carbs around activity, and healthy fats. You don't need to cut any food group — just the total.
Common mistakes that stall fat loss
- Underestimating intake. Untracked oils, sauces, drinks, and "bites" add up fast. Track honestly for a while.
- Over-restricting then binging. Too steep a deficit backfires. Choose a deficit you can live with.
- Drinking your calories. Sodas, juices, fancy coffees, and alcohol are easy to overlook.
- Ignoring protein. Low protein means more muscle lost and more hunger.
- Chasing the daily scale. Weight bounces day to day. Watch the weekly trend.
Frequently asked questions
How many calories should I eat to lose weight?
Estimate your maintenance calories (roughly bodyweight in lb × 14–16 depending on activity), then eat about 500 below that for roughly 1 lb of loss per week. Track for a few weeks and adjust based on your weekly average weight.
Is a 1,200-calorie diet healthy?
For many people it's too low to sustain and can leave you hungry, tired, and short on nutrients. Most people do better with a moderate deficit from a higher intake. Treat very low intakes as a general floor, not a goal.
Do I have to count calories forever?
No. Tracking for a few weeks teaches you portion sizes and which foods cost you the most. Many people then maintain results using those habits without logging every bite.
Why am I not losing weight in a deficit?
Usually the deficit isn't as big as it seems — untracked calories, larger portions, or being less active than estimated. Track honestly for two weeks and check your weekly average weight before changing anything.
The bottom line
To lose weight, eat in a moderate calorie deficit — roughly 500 calories below your maintenance level — get plenty of protein, and adjust based on your weekly average weight. Pick a deficit you can actually live with, because the slow, sustainable approach is the one that keeps the fat off.
Next, read our healthy eating for weight loss meal plan and how to lose fat as a beginner.
