What is the BMR for a 42-year-old man?

The estimated BMR (basal metabolic rate) for a 42-year-old man of average height and weight is 1779 kcal/day, calculated using the Mifflin-St Jeor equation.

Calorie Guide · Age 42

Calories for a 42-Year-Old Man

Q: How many calories does a 42-year-old man need?

A lightly active 42-year-old man of average weight and height needs approximately 2446 kcal/day to maintain weight. Sedentary needs are around 2134 kcal, and very active around 3068 kcal.

Q: How many calories should a 42-year-old man eat to lose weight?

A 42-year-old man should eat approximately 1946 kcal/day to lose about 0.5 kg (1 lb) per week. This is a 500 kcal deficit from the estimated maintenance of 2446 kcal.

BMR, TDEE and exact calorie targets for weight loss, maintenance and muscle gain at age 42.

Calorie Needs at Age 42 — Average Man

1779

BMR (at rest)

2134

Sedentary TDEE

2446
Lightly active TDEE

2757

Moderately active

1946

Weight loss target

2446

Maintenance

2746

Muscle gain target

How Many Calories Does a 42-Year-Old Man Need?

Using the Mifflin-St Jeor equation with average US height and weight for a man aged 42, the resting metabolic rate (BMR) is approximately 1779 kcal/day. With typical daily activity included, total calorie expenditure (TDEE) ranges from 2134 kcal (sedentary) to 3068 kcal (very active).

Age 42 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	1696 kcal	~0.75 kg/week
📉 Weight loss	1946 kcal	~0.5 kg/week
✅ Maintenance	2446 kcal	Weight stable
💪 Lean bulk	2746 kcal	~0.25 kg/week
🏋️ Aggressive bulk	2946 kcal	~0.5 kg/week

Calorie Needs by Activity Level

Activity Level	Description	Daily Calories
Sedentary	Desk job, minimal movement	2134 kcal
Lightly active	1–3 workouts/week	2446 kcal
Moderately active	3–5 workouts/week	2757 kcal
Very active	Hard training 6–7 days/week	3068 kcal

How Metabolism Changes Around Age 42

Metabolic rate declines approximately 1–2% per decade after age 30, driven primarily by muscle loss (sarcopenia) rather than any inherent slowdown. At age 42, your BMR of 1779 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 42
32	1829 kcal	+50 kcal
37	1804 kcal	+25 kcal
42	1779 kcal	—
47	1754 kcal	-25 kcal
52	1729 kcal	-50 kcal

Macronutrient Split at 2446 kcal

Macro	% of Calories	Grams/day	Calories
Protein	30%	183 g	732 kcal
Carbohydrates	40%	245 g	980 kcal
Fat	30%	82 g	738 kcal

At age 42, 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 42-year-old man need per day?A lightly active 42-year-old man of average size needs approximately 2446 kcal/day to maintain weight. This ranges from 2134 kcal (sedentary) to 3068 kcal (very active).

How many calories should a 42-year-old man eat to lose weight?Aim for 1946 kcal/day — a 500 kcal deficit from the 2446 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 42 affect how many calories you burn?Yes. Every decade after 30, BMR drops ~1–2% mainly due to muscle loss. At age 42 the estimated BMR is 1779 kcal — compare to 1839 kcal at age 30. Resistance training largely offsets this decline.

Related Age Guides

Sources

WHO CDC Mifflin-St Jeor (PubMed)