What is the BMR for a 40-year-old man?

The estimated BMR (basal metabolic rate) for a 40-year-old man of average height and weight is 1789 kcal/day, calculated using the Mifflin-St Jeor equation.

Calorie Guide · Age 40

Calories for a 40-Year-Old Man

Q: How many calories does a 40-year-old man need?

A lightly active 40-year-old man of average weight and height needs approximately 2459 kcal/day to maintain weight. Sedentary needs are around 2146 kcal, and very active around 3085 kcal.

Q: How many calories should a 40-year-old man eat to lose weight?

A 40-year-old man should eat approximately 1959 kcal/day to lose about 0.5 kg (1 lb) per week. This is a 500 kcal deficit from the estimated maintenance of 2459 kcal.

BMR, TDEE and exact calorie targets for weight loss, maintenance and muscle gain at age 40.

Calorie Needs at Age 40 — Average Man

1789

BMR (at rest)

2146

Sedentary TDEE

2459
Lightly active TDEE

2772

Moderately active

1959

Weight loss target

2459

Maintenance

2759

Muscle gain target

How Many Calories Does a 40-Year-Old Man Need?

Using the Mifflin-St Jeor equation with average US height and weight for a man aged 40, the resting metabolic rate (BMR) is approximately 1789 kcal/day. With typical daily activity included, total calorie expenditure (TDEE) ranges from 2146 kcal (sedentary) to 3085 kcal (very active).

Age 40 note: Metabolism begins slowing ~1–2% per decade after 30. Maintaining muscle through resistance training and adequate protein (0.7–1 g/lb) offsets most of this decline.

Calorie Targets by Goal

Goal	Daily Calories	Expected Result
🔵 Aggressive weight loss	1709 kcal	~0.75 kg/week
📉 Weight loss	1959 kcal	~0.5 kg/week
✅ Maintenance	2459 kcal	Weight stable
💪 Lean bulk	2759 kcal	~0.25 kg/week
🏋️ Aggressive bulk	2959 kcal	~0.5 kg/week

Calorie Needs by Activity Level

Activity Level	Description	Daily Calories
Sedentary	Desk job, minimal movement	2146 kcal
Lightly active	1–3 workouts/week	2459 kcal
Moderately active	3–5 workouts/week	2772 kcal
Very active	Hard training 6–7 days/week	3085 kcal

How Metabolism Changes Around Age 40

Metabolic rate declines approximately 1–2% per decade after age 30, driven primarily by muscle loss (sarcopenia) rather than any inherent slowdown. At age 40, your BMR of 1789 kcal reflects your current muscle mass, height and hormonal status. The single most effective way to maintain or raise your BMR is resistance training — each kilogram of lean muscle burns roughly 13 kcal/day at rest.

Age	Estimated BMR (man)	Change vs age 40
30	1839 kcal	+50 kcal
35	1814 kcal	+25 kcal
40	1789 kcal	—
45	1764 kcal	-25 kcal
50	1739 kcal	-50 kcal

Macronutrient Split at 2459 kcal

Macro	% of Calories	Grams/day	Calories
Protein	30%	184 g	736 kcal
Carbohydrates	40%	246 g	984 kcal
Fat	30%	82 g	738 kcal

At age 40, protein intake is especially important. Aim for at least 71–89 g/day to maintain muscle mass, whether you're in a deficit, at maintenance, or in a surplus.

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Frequently Asked Questions

How many calories does a 40-year-old man need per day?A lightly active 40-year-old man of average size needs approximately 2459 kcal/day to maintain weight. This ranges from 2146 kcal (sedentary) to 3085 kcal (very active).

How many calories should a 40-year-old man eat to lose weight?Aim for 1959 kcal/day — a 500 kcal deficit from the 2459 kcal maintenance estimate — to lose approximately 0.5 kg per week. Never go below 1200 kcal (women) or 1500 kcal (men) for extended periods.

Does age 40 affect how many calories you burn?Yes. Every decade after 30, BMR drops ~1–2% mainly due to muscle loss. At age 40 the estimated BMR is 1789 kcal — compare to 1839 kcal at age 30. Resistance training largely offsets this decline.

Related Age Guides

Sources

WHO CDC Mifflin-St Jeor (PubMed)