How Many Calories Should I Eat Per Day? (TDEE Explained)
Updated May 2026 · 7 min read
This is one of the most searched nutrition questions online, and the generic answers — "women need 2,000, men need 2,500" — are almost meaningless in practice. Those are averages that could be off by 600–800 calories for any individual. Here's how to actually find your number.
Step 1: Understand the Two Key Numbers
Everything starts with two figures: BMR and TDEE.
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to keep your heart beating, lungs breathing, and organs functioning. Think of it as the fuel cost of being alive. For most people, BMR accounts for 60–75% of total daily calorie burn.
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by your activity level. It's the total number of calories you burn in a typical day including exercise, walking, and even fidgeting. Eating at your TDEE maintains your current weight exactly.
Step 2: Calculate Your BMR
The Mifflin-St Jeor equation is the most accurate BMR formula for most people — it was validated against measured metabolic rates in multiple large studies and is what most dietitians use today.
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
A worked example: a 30-year-old woman who weighs 65 kg and is 165 cm tall. BMR = (10 × 65) + (6.25 × 165) − (5 × 30) − 161 = 650 + 1031.25 − 150 − 161 = 1,370 kcal/day.
Step 3: Multiply by Your Activity Level
Activity Level
Description
Multiplier
Sedentary
Desk job, little to no exercise
× 1.2
Lightly active
Light exercise 1–3 days/week
× 1.375
Moderately active
Moderate exercise 3–5 days/week
× 1.55
Very active
Hard exercise 6–7 days/week
× 1.725
Extra active
Physical job + hard daily exercise
× 1.9
Using our example: the 30-year-old woman is moderately active (gym 4× per week). 1,370 × 1.55 = 2,124 kcal/day TDEE. That's what she needs to eat to maintain her weight — considerably more than the generic "2,000 for women."
Don't do this by hand. Our free calorie calculator runs the Mifflin-St Jeor equation and all five activity multipliers for you, and shows maintenance, weight loss, and muscle-gain targets in one view.
Step 4: Adjust for Your Goal
Once you have your TDEE, the adjustments are simple arithmetic:
To lose weight: Eat 300–500 kcal below TDEE for sustainable fat loss (~0.3–0.5 kg per week). A 500-calorie deficit produces about 0.5 kg/week. For most people, this is the sweet spot — aggressive enough to make progress, gentle enough to preserve muscle and maintain energy.
To maintain weight: Eat at TDEE.
To gain muscle: Eat 200–300 kcal above TDEE (a "lean bulk"). This is enough of a surplus for muscle growth without excessive fat gain.
One thing people often miss: your TDEE changes as you lose weight. A lighter body burns fewer calories. If you lose 5–10 kg, your TDEE drops meaningfully — recalculate every couple of months to keep your targets accurate.
Why Calorie Counting Is Hard (and How to Make It Easier)
The maths is simple but the execution is notoriously difficult. Research shows people underestimate their food intake by an average of 20–30% — even when they think they're tracking carefully. This is why someone eating "1,800 calories" by their own estimate might actually be consuming 2,200.
A few things genuinely help:
Weigh food, don't measure by volume. A tablespoon of peanut butter can vary by 50% depending on how generously you scoop. 30g of peanut butter is always 30g.
Track for two weeks, not forever. Even a short tracking period builds a mental model of your real intake that persists afterward.
Don't ignore liquids. Coffee drinks, juices, and smoothies are common sources of invisible calories — a large-size latte can add 250–400 kcal without feeling like "eating."
A Note on Metabolism Myths
Metabolisms don't vary as wildly as people think. The difference in BMR between a person with a "fast metabolism" and a "slow metabolism" of the same height, weight, age and sex is typically only 100–200 calories — not 500 or 1,000 as is often claimed. The bigger variable is activity: NEAT (non-exercise activity thermogenesis — fidgeting, walking around, standing) can vary by 300–700 calories between active and sedentary people of the same size. That's the real reason some people seem to eat more and gain less.
Find Your Personal Calorie Target
Mifflin-St Jeor formula, metric and imperial, all five activity levels. Free, no signup.
A deficit of 500 calories per day below your TDEE produces roughly 0.5 kg (1 lb) of fat loss per week — the rate most dietitians recommend. A 1,000 calorie deficit produces about 1 kg (2 lbs) per week, which is generally the recommended maximum. Going below 1,200 kcal/day (women) or 1,500 kcal/day (men) can be counterproductive without medical supervision.
It depends on size, age, and activity level. The average sedentary adult woman needs around 1,600–2,000 kcal/day to maintain weight. An active woman might need 2,200–2,600 kcal/day. Use a TDEE calculator with your specific details rather than generic averages.
The average sedentary adult man needs roughly 2,000–2,500 kcal/day. An active or large man might need 2,800–3,500 kcal/day. TDEE is highly individual — age, height, weight, and activity all matter significantly. Calculate your personal TDEE rather than using averages.
Three common causes: (1) Calorie tracking errors — most people underestimate intake by 20–30%, especially from oils, condiments, and drinks. Weigh food for one week to check accuracy. (2) Metabolic adaptation — prolonged very low-calorie diets lower TDEE through adaptive thermogenesis. A one-week diet break at maintenance can partially reset this. (3) Water retention masking fat loss — stress, high sodium, and hormonal changes can cause temporary weight gain from water even when fat is being lost.