Calorie needs at age 18, female
TDEE is the number of calories you burn in a day. This page works it out for a 18-year-old woman at 5 ft 4 in and 150 lb, then shows how it changes with activity.
How it works
Your body burns calories at rest. The page estimates that with the Mifflin-St Jeor equation: 10 times weight in kilograms plus 6.25 times height in centimeters minus 5 times age, then plus 5 for males or minus 161 for females. It multiplies the result by an activity factor from 1.2 to 1.9 to get your daily total. At 150 lb the weight term for this 18-year-old woman is 680.4, at the lightly active level.
Worked example
A woman aged 18 is 162.56 cm tall and weighs 68.04 kg. Multiply weight by 10: 10 × 68.04 = 680.4. Multiply height by 6.25: 6.25 × 162.56 = 1016. Subtract 5 × 18 = 90. Subtract 161. The total is 1445.4, or 1445 calories at rest. Multiply 1445.4 by 1.375 for the lightly active level. That gives 1987.4, or 1987 calories a day.
Maintenance calories at every activity level for the same woman aged 18 at 5 ft 4 in and 150 lb, with the lightly active level set in the form above.
- Sedentary (little or no exercise)
- 1734 calories a day
- Lightly active (light exercise 1 to 3 days a week)
- 1987 calories a day
- Moderately active (moderate exercise 3 to 5 days a week)
- 2240 calories a day
- Very active (hard exercise 6 to 7 days a week)
- 2493 calories a day
- Extra active (very hard exercise and a physical job)
- 2746 calories a day
Common questions
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 woman aged 18 at 150 lb, BMR is 1445 calories and TDEE at the lightly active level is 1987.
Which activity level should I pick?
Pick the one that matches a typical week, not your best week. If you sit most of the day and train a few times, lightly or moderately active is usually closer than very active. Across the five levels this 18-year-old woman ranges from 1734 to 2746 calories a day, and the lightly active level gives 1987.
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 1487 calories a day for this 18-year-old woman 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 2237 calories a day for this 18-year-old woman at the lightly active level.
Why does age 18 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 18 that is 90 calories. Without the age term this 18-year-old woman would burn 1535 calories at rest, or 2111 a day at the lightly active level.