Calorie needs at age 31, male
This page estimates total daily energy use. The sample is a man aged 31 at 5 ft 10 in and 178 lb, and the table shows every activity level.
How it works
Daily calories equal resting calories times an activity factor. Resting calories come from Mifflin-St Jeor: 10 times kilograms plus 6.25 times centimeters minus 5 times age, with 5 added for males or 161 taken off for females. The factor runs from 1.2 to 1.9. For a man aged 31 at the lightly active level the fixed adjustment is plus 5.
Worked example
Say a man aged 31 is 5 ft 10 in tall and weighs 178 lb. That is 177.8 cm and 80.74 kg. The weight term is 10 × 80.74 = 807.4. The height term is 6.25 × 177.8 = 1111.25. The age term is 5 × 31 = 155. Add 5. The result is 1768.65 at rest. Times 1.375 for the lightly active level is 2431.9, which rounds to 2432 calories a day.
Maintenance calories at every activity level for the same man aged 31 at 5 ft 10 in and 178 lb, with the lightly active level set in the form above.
- Sedentary (little or no exercise)
- 2122 calories a day
- Lightly active (light exercise 1 to 3 days a week)
- 2432 calories a day
- Moderately active (moderate exercise 3 to 5 days a week)
- 2741 calories a day
- Very active (hard exercise 6 to 7 days a week)
- 3051 calories a day
- Extra active (very hard exercise and a physical job)
- 3360 calories a day
Common questions
How big a calorie deficit is reasonable for weight loss?
A deficit of 500 calories a day is a common starting point and works out to roughly half a kilogram a week. Smaller deficits are slower and easier to keep up. A 500 calorie deficit here means 1932 calories a day for this 31-year-old man at the lightly active level.
How big a surplus helps build muscle?
A modest surplus of about 250 calories a day is a common starting point. Larger surpluses tend to add more fat without adding muscle faster. A 250 calorie surplus here means 2682 calories a day for this 31-year-old man at the lightly active level.
Why does age 31 change the result?
The formula takes 5 calories off for every year of age, which reflects that resting burn tends to fall over time. At 31 that is 155 calories. Without the age term this 31-year-old man would burn 1924 calories at rest, or 2645 a day at the lightly active level.
How accurate is a calorie estimate?
It is a starting estimate. Track your weight over two or three weeks and adjust the target up or down based on what actually happens. For this 31-year-old man, a 5 percent error on 2432 calories is 122 calories a day.
What is the difference between BMR and TDEE?
BMR is what your body burns at rest. TDEE adds the calories you use moving and exercising. It is always higher. For this man aged 31 at 178 lb, BMR is 1769 calories and TDEE at the lightly active level is 2432.