How to Calculate Daily Calorie Needs for Weight Maintenance
Quick Take
Weight maintenance calories equal your total daily energy expenditure (TDEE). Calculate it in three steps: (1) estimate your BMR using the Mifflin-St Jeor formula, (2) multiply by your activity factor, (3) adjust based on actual weekly weight change. That final number is your maintenance calorie target.
"How many calories should I eat to maintain my weight?" is one of the most common questions in nutrition. The honest answer: it depends on you. Your maintenance calorie level — the number of calories you need to consume to keep your body weight stable — is as individual as your fingerprint. It depends on your body size, age, sex, activity level, muscle mass, metabolism, and even the temperature of your environment.
The good news is that you do not need a lab test to estimate this number. You can calculate a reasonable approximation using a three-step process that anyone can do at home. In this article we walk through the complete calculation, explain what each component means, and show you how to refine the number based on real-world weight tracking.
For instant calculations, use the TDEE Calculator on VivMetric, which uses the Mifflin-St Jeor BMR formula with an activity factor adjustment. The BMR Calculator gives you just the baseline resting metabolism number if you want to start from scratch.
What Does "Maintenance Calories" Actually Mean?
At its simplest, weight maintenance means caloric equilibrium: the calories you consume equal the calories you burn. When this balance holds, your body weight stays roughly stable over time — not perfectly static, since daily fluctuations from water and glycogen are normal, but without a net gain or loss over weeks and months.
The number that matters is your total daily energy expenditure, or TDEE. TDEE represents all the calories your body burns in a typical day, including:
Resting metabolic rate (RMR): The calories needed just to keep your body alive — breathing, circulating blood, maintaining organ function, repairing cells. This accounts for roughly 60 to 70 percent of total daily expenditure for most people.
Thermic effect of food (TEF): The calories used to digest, absorb, and process the food you eat. This typically accounts for 5 to 10 percent of daily expenditure, with protein having the highest TEF and fat the lowest.
Non-exercise activity thermogenesis (NEAT): Calories burned through everyday movements — walking to the car, typing, cooking, fidgeting. This component varies enormously between individuals and can account for 10 to 30 percent of daily expenditure.
Exercise activity thermogenesis (EAT): Calories burned through structured exercise. This is the most variable component and can range from near zero (for sedentary individuals) to 30 percent or more of total expenditure for highly active people.
Step 1: Calculate Your BMR
The first step is estimating your resting metabolic rate. The Mifflin-St Jeor formula, published in 1990 and validated against indirect calorimetry data, is considered the most accurate equation for estimating BMR from basic inputs. It requires only your weight, height, age, and biological sex.
The Mifflin-St Jeor Formula (Metric Units)
For men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 5
For women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161
Worked Example
Let us take a 35-year-old woman who is 5'7" (170 cm) and weighs 150 pounds (68 kg). Using the formula: 10 × 68 + 6.25 × 170 - 5 × 35 - 161 = 680 + 1,062.5 - 175 - 161 = 1,406.5 kcal per day for her BMR.
For a 40-year-old man at the same height and weight (68 kg, 170 cm): 10 × 68 + 6.25 × 170 - 5 × 40 - 5 = 680 + 1,062.5 - 200 - 5 = 1,537.5 kcal per day.
Notice that men have a higher BMR than women of the same weight and height, even with identical inputs. The sex adjustment (−161 for women vs −5 for men) reflects the biological difference in average lean body mass between sexes — men typically carry more muscle, which is metabolically active tissue.
The BMR Calculator on VivMetric handles this calculation automatically and supports both imperial and metric inputs.
Step 2: Apply an Activity Factor
BMR represents only the calories you would burn lying completely still all day. To get a realistic daily number, you multiply BMR by an activity factor that accounts for your typical movement and exercise. The following activity factor scale is based on the original Mifflin-St Jeor validation and is widely used in clinical nutrition:
| Activity Level | Factor | Description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise, desk job |
| Lightly Active | 1.375 | Light exercise 1–3 days per week |
| Moderately Active | 1.55 | Moderate exercise 3–5 days per week |
| Very Active | 1.725 | Hard exercise 6–7 days per week |
| Extremely Active | 1.9 | Physically demanding job + daily intense training |
Continuing the Example
Our 35-year-old woman with a BMR of 1,406.5 kcal does moderate exercise three days per week. Her estimated TDEE = 1,406.5 × 1.55 = approximately 2,180 kcal per day. This is her estimated maintenance calorie level — the number of calories she would need to consume daily to maintain her current weight.
For the 40-year-old man with a BMR of 1,537.5 kcal who is lightly active: 1,537.5 × 1.375 = approximately 2,114 kcal per day.
The TDEE Calculator on VivMetric provides a slider-based activity selector and displays the full step-by-step calculation so you can understand how the number was derived.
Step 3: Refine With Real-World Tracking
Here is where most calculators stop — but this is where the real value lies. The formula-based estimate is a starting point, not a final answer. Your actual maintenance calorie level may differ by 10 to 20 percent from the calculated number due to individual variations in NEAT, metabolism, and food thermogenesis.
To refine the estimate, track two things for two to four weeks:
1. Your daily calorie intake. Use a food tracking app or a simple journal to record everything you eat and drink. Weigh or measure foods when possible and be as accurate as possible — undercounting is the single biggest source of error in calorie tracking.
2. Your morning weight. Weigh yourself first thing every morning after using the bathroom and before eating. Track the daily readings and calculate a weekly average.
After two to four weeks, compare the trend in your weight against your average daily calorie intake. If your weight is stable, your average intake is your actual maintenance level. If you are losing weight, you are eating below maintenance. If you are gaining, you are eating above it. Adjust your daily intake by approximately 100 to 200 calories per day and observe for another two weeks to dial in the number.
Why Maintenance Calories Change Over Time
Your maintenance calorie level is not static. Several factors can shift it upward or downward:
Weight changes. As you lose weight, your BMR decreases because a smaller body burns fewer calories at rest. As you gain lean mass, your BMR increases because muscle is metabolically active tissue. This is why long-term weight loss requires periodic calorie adjustment — a phenomenon known as adaptive thermogenesis or "metabolic adaptation."
Activity changes. Starting a new exercise routine, taking up a physically demanding job, or recovering from an injury all shift your activity factor. Remember that NEAT — spontaneous movement — also changes as your fitness level improves.
Aging. After roughly age 30, BMR declines by about 1 to 2 percent per year due to gradual loss of lean muscle mass. Regular resistance training can offset this decline significantly.
Environment. Colder temperatures increase energy expenditure as your body works to maintain core temperature. Altitude, humidity, and even the calories in your diet (via TEF) can produce measurable shifts.
Practical Tips for Maintaining Your Weight
Calculating your maintenance calorie level is one step. Consistently hitting that target is the real challenge. Here are a few evidence-based strategies:
Track consistently. Use the TDEE Calculator to establish your baseline, then track actual intake and weight trends. Review and adjust every two to four weeks.
Prioritize protein. A higher-protein diet (25 to 30 percent of calories) increases TEF, preserves lean mass during weight loss, and promotes satiety — all of which make it easier to maintain a stable weight without constant hunger.
Strength train. Resistance training two to three times per week preserves and builds lean mass, which keeps your BMR higher and makes maintenance easier in the long term. Use the Lean Body Mass Calculator to track your progress.
Adjust before drastic changes. Small, systematic adjustments (100–200 calories per day) are more sustainable than large swings. Avoid radical cuts that are difficult to maintain over time.