Calorie Needs (TDEE)
Calorie Needs (TDEE) Calculator — Know Exactly How Many Calories You Need
Introduction:
“How many calories should I eat?” is one of the most common questions in health and fitness — and one of the hardest to answer with a single number, because the honest answer depends on your height, weight, age, sex, and how active you are.
That number has a name: TDEE, or Total Daily Energy Expenditure. It represents the total calories your body burns in a day, including everything from basic survival functions (breathing, digestion, circulation) to the energy spent on movement and exercise. Knowing your TDEE is the foundation for almost every nutrition goal — whether you want to lose weight, gain muscle, or simply maintain where you are.
The MyHealthChart Calorie Needs (TDEE) Calculator uses two of the most clinically recognized formulas — Mifflin-St Jeor and Harris-Benedict — to estimate this number for you, along with a practical macro breakdown so you know not just how much to eat, but roughly what to eat it as.
How to Use the Calorie Needs Calculator:
Getting your personalized number takes about a minute:
- Choose your unit system — Metric (kg/cm) or Imperial (lb/ft & inches).
- Pick your preferred formula — Mifflin-St Jeor (the modern default, generally considered more accurate) or Harris-Benedict (the long-standing classic).
- Enter your height and weight.
- Enter your age.
- Select your sex — this affects the formula, since body composition differs between sexes at the same height and weight.
- Choose your activity level from the five options, ranging from Sedentary to Extremely Active — be honest here, since this is the step most people get wrong.
- Click “Calculate My Calorie Needs” — your TDEE, BMR, a mild deficit target, and a suggested macro breakdown all appear instantly.
No data is stored or saved. You can recalculate as often as your weight, activity level, or goals change.
The Method Behind the Calculation:
The calculator works in two stages: first estimating your BMR (Basal Metabolic Rate — the calories you’d burn lying still all day), then multiplying that by an activity multiplier to get your TDEE.
Mifflin-St Jeor Equation (default, considered more accurate for most modern populations):
Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Harris-Benedict Equation (revised version, still widely used):
Men: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) − (5.677 × age)
Women: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) − (4.330 × age)
Activity Multipliers (applied to BMR to get TDEE):
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | × 1.2 | Little or no exercise, desk job |
| Lightly Active | × 1.375 | Light exercise 1–3 days/week |
| Moderately Active | × 1.55 | Moderate exercise 3–5 days/week |
| Very Active | × 1.725 | Hard exercise 6–7 days/week |
| Extremely Active | × 1.9 | Physical job plus daily intense training |
Macro Breakdown is calculated from your TDEE using a balanced split: 30% protein, 40% carbohydrates, and 30% fat — converted to grams using 4 calories per gram for protein and carbs, and 9 calories per gram for fat.
Tips for Getting an Accurate Result:
After calculating, you’ll see four key numbers and a macro breakdown:
- BMR (Basal Metabolic Rate)
This is the energy your body burns at complete rest — just to keep your heart beating, lungs breathing, and organs functioning. It’s always your lowest number, since it doesn’t include any movement or activity.
- Maintain (TDEE)
This is your full daily calorie burn, including your activity level. Eating roughly this amount keeps your weight stable over time — this is your baseline number for any goal.
Mild Deficit
This number subtracts roughly 250 calories from your TDEE, targeting a gentle, sustainable rate of fat loss (approximately 0.25 kg, or about half a pound, per week). This is generally easier to stick to long-term than aggressive deficits.
Macro Breakdown (Protein / Carbs / Fat)
These three numbers translate your calorie target into grams of each macronutrient, based on a balanced 30/40/30 split — giving you a practical target to aim for across meals, rather than just a total calorie number.
To gain weight, you would eat above your Maintain number; to lose weight, you would eat below it (the Mild Deficit number is a reasonable starting point); to maintain, you’d aim to eat close to your TDEE consistently.
Reading Your Results & Guide:
- Be honest about your activity level — this is the #1 source of error. Most people overestimate how active they really are. If you’re not sure, round down rather than up.
- Use your current, real weight, not a goal weight — TDEE reflects what your body burns right now, not what it will burn after you’ve lost or gained weight.
- Recalculate as your weight changes. Your calorie needs shift as your body weight changes, so a number calculated at 80 kg won’t be accurate once you reach 70 kg.
- Mifflin-St Jeor is generally the better default for most people, as it tends to be more accurate across a wider range of body types than Harris-Benedict, which was developed nearly a century earlier on a more limited population.
- Use the Mild Deficit number as a sustainable starting point, not the most aggressive option. A deficit of roughly 250 calories/day supports gradual, sustainable fat loss without being extreme.
- Treat the macro split as a flexible guide, not a strict rule. The 30/40/30 split works well for general health, but specific goals (like strength training or certain medical conditions) may call for a different ratio — worth discussing with a nutritionist if you have specific performance or medical goals.
Important Limitations to Keep in Mind:
This calculator provides a scientifically grounded estimate, not a measured value. Both formulas were developed using population averages, so your actual metabolism can vary by 100–200 calories or more in either direction due to factors like genetics, muscle mass, hormonal conditions (such as thyroid disorders), and metabolic adaptation from prior dieting.
The activity multiplier is also a broad estimate — two people who both consider themselves “moderately active” can have meaningfully different real-world calorie burns depending on the specific type, intensity, and duration of their activity.
Use this calculator as a strong starting point, then adjust based on real-world results: if your weight isn’t changing the way you expect after 2–3 weeks at a given calorie target, that’s more reliable feedback than the formula alone. For specific medical or performance goals, consult a doctor or registered dietitian.
Frequently Asked Questions:
1. What does TDEE mean on MyHealthChart?
TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a day, including rest and activity. My Health Chart’s Calorie Needs Calculator estimates this number using your height, weight, age, sex, and activity level.
2. Which formula should I choose on the MyHealthChart calculator — Mifflin-St Jeor or Harris-Benedict?
MyHealthChart defaults to Mifflin-St Jeor, since it’s generally considered more accurate for most modern body types. Harris-Benedict is an older, still widely used formula and is included on My HealthChart as an alternative if you prefer to compare both results.
3. How accurate is the MyHealthChart TDEE calculator?
The MyHealthChart Calorie Needs Calculator uses scientifically validated formulas, but like any TDEE calculator, it provides an estimate based on population averages. Your actual metabolism can vary by 100–200 calories or more depending on individual factors like muscle mass and genetics, so MyHealthChart recommends adjusting based on real-world results over a few weeks.
4. How do I lose weight using the MyHealthChart Calorie Needs Calculator?
To lose weight, MyHealthChart suggests using the Mild Deficit number shown in your results, which targets a gentle, sustainable rate of fat loss of about 0.25 kg per week. Eating consistently below your Maintain (TDEE) number is the basic principle behind weight loss.
5. Why does MyHealthChart show a macro breakdown along with my calorie number?
MyHealthChart includes a macro breakdown — protein, carbs, and fat in grams — because a total calorie number alone doesn’t tell you what to actually eat. The breakdown is based on a balanced 30% protein, 40% carbs, and 30% fat split of your maintenance calories.
6. Is my data saved when I use the MyHealthChart TDEE Calculator?
No. MyHealthChart calculates your results instantly in your browser and does not store, save, or share any of the information you enter. You can use the My Health Chart Calorie Needs Calculator as many times as you like with no sign-up required.
7. Why does My Health Chart ask me to choose an activity level so specifically?
MyHealthChart asks for a specific activity level because it’s the single biggest factor affecting your TDEE beyond your basic body stats. Most people overestimate their activity level, so MyHealthChart provides clear descriptions for each option to help you choose accurately.