How Many Calories Should I Eat to Lose Weight? (Calculator Guide)

The Formula Is Simple. Doing It Right Is What Matters.

The number of calories you should eat to lose weight is your Total Daily Energy Expenditure (TDEE) minus 300-500 calories. That is the entire formula. Everything else, every diet book, every meal plan, every weight loss programme, is just a different way of achieving this one thing: a sustained calorie deficit.

But while the formula is simple, applying it correctly requires knowing your TDEE, choosing an appropriate deficit size, eating the right foods to make that deficit sustainable, and being patient enough to let the results accumulate over weeks and months.

This guide walks you through each step with real numbers and practical examples.

Step 1: Calculate Your BMR

Your Basal Metabolic Rate is the number of calories your body burns at complete rest to maintain basic functions: breathing, circulation, cell repair, and organ function. This is your physiological floor, the energy your body needs regardless of activity.

Use the Mifflin-St Jeor equation, which research has shown to be the most accurate widely available formula.

For men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 5 For women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161

Example 1 (man): 35 years old, 85kg, 178cm tall. BMR = (10 x 85) + (6.25 x 178) - (5 x 35) - 5 = 850 + 1,113 - 175 - 5 = 1,783 calories

Example 2 (woman): 28 years old, 68kg, 163cm tall. BMR = (10 x 68) + (6.25 x 163) - (5 x 28) - 161 = 680 + 1,019 - 140 - 161 = 1,398 calories

Step 2: Multiply by Activity Level

Your TDEE accounts for all movement beyond your BMR. Multiply your BMR by the appropriate activity factor.

Sedentary (desk job, no exercise): BMR x 1.2. Lightly active (light exercise 1-3 days per week): BMR x 1.375. Moderately active (moderate exercise 3-5 days per week): BMR x 1.55. Very active (hard exercise 6-7 days per week): BMR x 1.725. Extremely active (athlete, physical job plus exercise): BMR x 1.9.

Example 1 continued (man, moderately active): TDEE = 1,783 x 1.55 = 2,764 calories Example 2 continued (woman, lightly active): TDEE = 1,398 x 1.375 = 1,922 calories

These are maintenance calories, the amount needed to stay at the same weight.

Step 3: Subtract for Weight Loss

For steady, sustainable fat loss that preserves muscle mass, subtract 300-500 calories from your TDEE.

Example 1 (man): 2,764 - 400 = 2,364 calories per day for weight loss Example 2 (woman): 1,922 - 400 = 1,522 calories per day for weight loss

At a 400-calorie daily deficit, both individuals would lose approximately 0.4kg (just under 1 pound) per week. Over 3 months, that is roughly 5kg of fat loss while maintaining muscle mass and energy levels.

Why 300-500 Calories Is the Sweet Spot

A smaller deficit (100-200 calories) produces very slow results that are difficult to see and easy to abandon. A larger deficit (700+ calories) triggers the cascade of negative adaptations discussed earlier: increased hunger, metabolic slowing, muscle loss, and hormonal disruption.

The 300-500 calorie range produces visible results within 2-3 weeks (enough to maintain motivation), preserves virtually all muscle mass when protein intake is adequate, maintains normal energy levels and hormonal function, does not require extreme food restriction, and has the highest long-term adherence rate in research studies.

What to Eat in Your Deficit

Not all deficits feel the same. A 1,500-calorie day of protein, vegetables, whole grains, and healthy fats feels dramatically different from 1,500 calories of white bread, juice, and candy. The first keeps you satisfied and nourished. The second leaves you hungry, tired, and craving more.

Protein first. Aim for at least 1.6g per kilogram of your body weight, and ideally 2.0g if you are strength training. For a 70kg person, that is 112-140g of protein per day. This preserves muscle, keeps you full, and costs more energy to digest than carbs or fat. Chicken breast, fish, eggs, Greek yogurt, beans, and lentils are the most protein-efficient sources. See our high protein food guide for the full list.

Vegetables at every meal. They provide volume, fiber, vitamins, and minerals for minimal calories. Filling half your plate with vegetables at lunch and dinner is the single easiest strategy for feeling full on fewer calories.

Smart carbohydrate choices. Choose whole grains over refined grains, fruits over juice, and beans over white bread. These provide more fiber and nutrients per calorie, keeping you fuller longer. For Nigerian food options, beans porridge, boiled yam, and moi moi are solid carbohydrate choices during a deficit.

Healthy fats in moderation. Fats are calorie-dense (9 calories per gram) so portions matter during a deficit, but they are essential for hormone production, brain function, and the absorption of fat-soluble vitamins. Include a thumb-sized portion of healthy fat at each meal from sources like avocado, olive oil, nuts, or fatty fish.

Tracking and Adjusting

Weigh yourself daily at the same time (morning, after using the bathroom, before eating) and calculate the weekly average. Daily weight fluctuates by 1-2kg due to water, food volume, and hormonal changes. Weekly averages reveal the true trend.

If your weekly average is dropping by 0.3-0.5kg, your deficit is working perfectly. If it is not moving after 2-3 consistent weeks, either your calorie estimate is too high (most common, usually from underestimating portions and cooking oils) or your TDEE estimate needs adjustment. Reduce intake by another 100-200 calories and reassess after two more weeks.

Use our food search tool to check the calorie content of what you are eating rather than estimating. The biggest source of error in calorie tracking is cooking oils (120 calories per tablespoon) and sauces, which most people significantly undercount.

The Timeline for Results

Expect to lose 0.3-0.5kg per week at a moderate deficit. In the first week, you may lose more (1-2kg) due to water loss, but this slows to the true fat loss rate from week two onward.

In one month: 1.5-2kg lost. In three months: 4-6kg lost. In six months: 8-12kg lost. In one year: 15-25kg lost.

These numbers may seem slow compared to marketing claims, but they represent real, permanent fat loss rather than temporary water manipulation. People who lose weight at this rate are dramatically more likely to maintain their results long-term than those who crash diet.

Explore the low calorie food guide for food ideas, the best Nigerian foods for weight loss, or the 7-day high protein meal plan for structured meal ideas.

All calculations are based on the Mifflin-St Jeor equation. Individual results vary based on genetics, body composition, adherence, and metabolic adaptation. Consult a healthcare professional before starting any weight loss programme.