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

The Simple Math of Weight Loss

Weight loss comes down to one principle: eat fewer calories than your body burns. This is called a calorie deficit. To lose 1 pound per week, you need a deficit of about 500 calories per day. For 2 pounds per week, that's a 1,000 calorie daily deficit.

But how do you know how many calories your body burns? That's where TDEE comes in.

What Is TDEE?

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a day, including:

1. BMR (Basal Metabolic Rate) — calories burned just to keep you alive (breathing, digestion, circulation). This accounts for 60-75% of your TDEE.

2. Activity calories — calories burned through exercise and daily movement (15-30%)

3. TEF (Thermic Effect of Food) — calories burned digesting food (about 10%)

How to Calculate Your TDEE

The most common formula is the Mifflin-St Jeor equation:

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

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

Then multiply your BMR by your activity level:

• Sedentary (desk job, little exercise): BMR × 1.2
• Lightly active (exercise 1-3 days/week): BMR × 1.375
• Moderately active (exercise 3-5 days/week): BMR × 1.55
• Very active (exercise 6-7 days/week): BMR × 1.725
• Extremely active (athlete/physical job + training): BMR × 1.9

Example Calculation

A 30-year-old woman who is 5'5" (165 cm), weighs 160 lbs (72.5 kg), and exercises 3 times per week:

• BMR = (10 × 72.5) + (6.25 × 165) - (5 × 30) - 161 = 1,407 calories
• TDEE = 1,407 × 1.55 = 2,181 calories

To lose 1 lb/week: 2,181 - 500 = 1,681 calories per day

To lose 2 lbs/week: 2,181 - 1,000 = 1,181 calories per day (caution: don't go below 1,200)

Safe Calorie Minimums

Never eat fewer than:

• 1,200 calories/day for women
• 1,500 calories/day for men

Going below these levels can cause muscle loss, nutrient deficiencies, metabolic slowdown, and other health problems. If your calculated deficit puts you below these numbers, aim for a slower rate of weight loss (0.5-1 lb/week).

How to Hit Your Calorie Target

Knowing your number is the first step. Consistently hitting it is where most people struggle. Here are practical tips:

Protein First

Aim for 0.7-1g of protein per pound of body weight. Protein keeps you fuller longer and preserves muscle during weight loss. A 160 lb person should target 112-160g of protein daily.

Track Your Meals

You can't manage what you don't measure. Use an app like BasedHealth to photograph your meals and automatically track calories. Even imperfect tracking is better than no tracking.

Don't Drink Your Calories

Soda, juice, fancy coffee drinks, and alcohol can add 300-800 calories per day without making you feel full. Switch to water, black coffee, or unsweetened tea.

Plan Your Meals

Spend 10 minutes on Sunday planning your meals for the week. People who meal plan consume 200-300 fewer calories per day on average compared to those who eat spontaneously.

Adjusting Over Time

Your TDEE isn't fixed. As you lose weight, your body burns fewer calories, so you'll need to recalculate every 10-15 pounds lost. This is why weight loss often stalls after a few months — your deficit has shrunk.

Apps like BasedHealth track your weight trends and help you adjust your calorie goals as you progress, so you don't have to do the math yourself.

Get Started

The best time to start is now. Calculate your TDEE using our Health Tools, set your calorie target, and start tracking with BasedHealth. Most users see results within the first two weeks.

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