A 6-foot man typically needs between 2,200 and 3,200 calories per day, depending on age, weight, and how active he is. That’s a wide range because a 25-year-old who trains five days a week and a 55-year-old with a desk job have very different energy demands, even at the same height. The best way to find your number is to estimate your baseline metabolism, then adjust for your lifestyle and goals.
Your Baseline: Resting Metabolic Rate
Your body burns a significant number of calories just keeping you alive: pumping blood, breathing, regulating temperature, repairing cells. This is your basal metabolic rate, or BMR, and it accounts for roughly 60 to 70 percent of the calories you burn each day. The most widely used formula for estimating it (the Mifflin-St Jeor equation) factors in your weight, height, and age.
For a 6-foot man, here’s what that looks like at different weights and ages:
- 180 lbs, age 30: roughly 1,815 calories per day
- 180 lbs, age 50: roughly 1,715 calories per day
- 200 lbs, age 30: roughly 1,905 calories per day
- 200 lbs, age 50: roughly 1,805 calories per day
- 220 lbs, age 40: roughly 1,905 calories per day
Notice that adding 20 pounds of body weight raises your BMR by about 90 calories, while aging 10 years drops it by about 50. These are just the calories your body needs at complete rest. You’ll need more than this to fuel your actual day.
Adjusting for Activity Level
To get your total daily calorie needs, you multiply your BMR by an activity factor. These multipliers have been validated in exercise science research and are the standard way dietitians estimate energy expenditure:
- Sedentary (desk job, little or no exercise): BMR × 1.2
- Lightly active (light exercise 1 to 3 days per week): BMR × 1.375
- Moderately active (moderate exercise 3 to 5 days per week): BMR × 1.55
- Very active (hard exercise 6 to 7 days per week): BMR × 1.725
To make this concrete, take a 6-foot, 180-pound, 30-year-old man with a BMR of about 1,815. If he’s sedentary, his daily calorie needs come to roughly 2,180. If he’s moderately active, that jumps to about 2,815. And if he’s training hard most days, he’s looking at around 3,130 calories to maintain his current weight. That’s nearly a 1,000-calorie difference based solely on how much he moves.
A 200-pound man of the same age and height who exercises moderately would need closer to 2,950 calories per day. Heavier bodies simply require more energy to move and maintain.
How Federal Guidelines Compare
The Dietary Guidelines for Americans provide calorie estimates for adult men based on age and activity level. These are useful as a sanity check, though they’re built around a reference man who is 5 feet 10 inches and 154 pounds, so a 6-foot man will generally land on the higher end of each range or slightly above it.
For men aged 26 to 45, the guidelines suggest 2,400 calories per day for sedentary individuals, 2,600 for moderately active, and 2,800 to 3,000 for active ones. Younger men in their early twenties get a slight bump (up to 3,000 even at moderate activity), and calorie needs taper gradually after 50. By age 61 to 65, the range drops to 2,000 for sedentary and 2,600 for active. Since you’re taller than the reference man used in these estimates, your actual needs are likely 100 to 200 calories above these figures.
How Metabolism Changes With Age
A common belief is that metabolism slows steadily from your twenties onward, but a large-scale study published in Science found something different. Metabolic rate stays remarkably stable between ages 20 and 60 when you account for changes in body composition. The real decline begins around age 60, when both total energy expenditure and resting metabolism start dropping by about 0.7 percent per year. By age 90, total daily energy expenditure is roughly 26 percent lower than in middle age.
What does change before 60 is body composition. Men tend to lose muscle and gain fat gradually from their thirties onward, and since muscle is more metabolically active than fat, this shift can make it feel like your metabolism is slowing. The practical takeaway: strength training matters more than age for keeping your calorie needs (and your metabolic health) stable through your forties and fifties.
Calories for Weight Loss
If your goal is to lose weight, the standard approach is to eat about 500 fewer calories per day than your maintenance level. This creates a deficit that translates to roughly half a pound to one pound of weight loss per week. For a moderately active, 6-foot, 200-pound man in his thirties whose maintenance sits around 2,950 calories, that means aiming for about 2,450 calories per day.
Cutting more aggressively can backfire. Very low calorie intakes make it harder to hold onto muscle, tend to increase hunger hormones, and are difficult to sustain. A moderate deficit lets you lose fat while still fueling workouts, keeping energy levels reasonable, and getting enough nutrients from your food. If the scale isn’t moving after two to three weeks at your target, dropping another 100 to 200 calories is a more sustainable adjustment than slashing your intake dramatically.
Calories for Muscle Gain
Building muscle requires a calorie surplus, but the “eat everything in sight” approach adds unnecessary fat. Current evidence supports a surplus of 300 to 500 calories above your maintenance level. This range provides enough extra energy to maximize muscle growth while limiting fat gain. For a moderately active 6-foot man maintaining at 2,800 calories, a lean bulk would mean eating 3,100 to 3,300 calories per day while following a progressive strength training program.
Protein intake matters here too. The baseline recommendation is 0.36 grams of protein per pound of body weight, but that’s the minimum for general health. If you’re actively training to build muscle, most sports nutrition guidelines suggest roughly double that amount, closer to 0.7 to 1 gram per pound. For a 180-pound man, that’s 125 to 180 grams of protein per day, spread across meals.
Finding Your Personal Number
Formulas give you a starting point, not a final answer. Individual variation in metabolism, non-exercise movement (how much you fidget, stand, walk around during your day), and even gut bacteria can shift your actual needs by a few hundred calories in either direction. The most reliable method is to pick a calorie target based on the estimates above, eat consistently at that level for two to three weeks, and track what happens to your weight.
If your weight holds steady, you’ve found your maintenance number. If you’re gaining about half a pound per week, you’re in a slight surplus. If you’re losing, you’re in a deficit. From there, adjust in increments of 200 to 300 calories until you’re trending in the direction you want. This self-experiment works better than any calculator because it accounts for all the variables a formula can’t capture.