What is the BMR for a 31-year-old man?

The estimated BMR (basal metabolic rate) for a 31-year-old man of average height and weight is 1834 kcal/day, calculated using the Mifflin-St Jeor equation.

Calorie Guide · Age 31

Calories for a 31-Year-Old Man

Q: How many calories does a 31-year-old man need?

A lightly active 31-year-old man of average weight and height needs approximately 2521 kcal/day to maintain weight. Sedentary needs are around 2200 kcal, and very active around 3163 kcal.

Q: How many calories should a 31-year-old man eat to lose weight?

A 31-year-old man should eat approximately 2021 kcal/day to lose about 0.5 kg (1 lb) per week. This is a 500 kcal deficit from the estimated maintenance of 2521 kcal.

BMR, TDEE and exact calorie targets for weight loss, maintenance and muscle gain at age 31.

Calorie Needs at Age 31 — Average Man

1834

BMR (at rest)

2200

Sedentary TDEE

2521
Lightly active TDEE

2842

Moderately active

2021

Weight loss target

2521

Maintenance

2821

Muscle gain target

How Many Calories Does a 31-Year-Old Man Need?

Using the Mifflin-St Jeor equation with average US height and weight for a man aged 31, the resting metabolic rate (BMR) is approximately 1834 kcal/day. With typical daily activity included, total calorie expenditure (TDEE) ranges from 2200 kcal (sedentary) to 3163 kcal (very active).

Age 31 note: Metabolism remains strong through your late twenties. This is the best window to build lean muscle mass — it raises your resting BMR long-term.

Calorie Targets by Goal

Goal	Daily Calories	Expected Result
🔵 Aggressive weight loss	1771 kcal	~0.75 kg/week
📉 Weight loss	2021 kcal	~0.5 kg/week
✅ Maintenance	2521 kcal	Weight stable
💪 Lean bulk	2821 kcal	~0.25 kg/week
🏋️ Aggressive bulk	3021 kcal	~0.5 kg/week

Calorie Needs by Activity Level

Activity Level	Description	Daily Calories
Sedentary	Desk job, minimal movement	2200 kcal
Lightly active	1–3 workouts/week	2521 kcal
Moderately active	3–5 workouts/week	2842 kcal
Very active	Hard training 6–7 days/week	3163 kcal

How Metabolism Changes Around Age 31

Metabolic rate declines approximately 1–2% per decade after age 30, driven primarily by muscle loss (sarcopenia) rather than any inherent slowdown. At age 31, your BMR of 1834 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 31
21	1884 kcal	+50 kcal
26	1859 kcal	+25 kcal
31	1834 kcal	—
36	1809 kcal	-25 kcal
41	1784 kcal	-50 kcal

Macronutrient Split at 2521 kcal

Macro	% of Calories	Grams/day	Calories
Protein	30%	189 g	756 kcal
Carbohydrates	40%	252 g	1008 kcal
Fat	30%	84 g	756 kcal

At age 31, 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.

Get personalized calorie targets based on your exact weight, height and activity level.

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Frequently Asked Questions

How many calories does a 31-year-old man need per day?A lightly active 31-year-old man of average size needs approximately 2521 kcal/day to maintain weight. This ranges from 2200 kcal (sedentary) to 3163 kcal (very active).

How many calories should a 31-year-old man eat to lose weight?Aim for 2021 kcal/day — a 500 kcal deficit from the 2521 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 31 affect how many calories you burn?Yes. Every decade after 30, BMR drops ~1–2% mainly due to muscle loss. At age 31 the estimated BMR is 1834 kcal — compare to 1839 kcal at age 30. Resistance training largely offsets this decline.

Related Age Guides

Sources

WHO CDC Mifflin-St Jeor (PubMed)