FemiFitCalc
Women's Health

Pregnancy Calorie Calculator

Quick answer

Estimate your daily calorie needs during pregnancy, adjusted for your pre-pregnancy stats, activity level and trimester. We calculate your pre-pregnancy BMR with the Mifflin-St Jeor equation, multiply it by your activity level for TDEE, then add the Institute of Medicine’s trimester adjustment.

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How daily calories are calculated

BMR (Mifflin-St Jeor, female) = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161

TDEE = BMR × activity factor (1.2 sedentary → 1.9 very active)

Total = TDEE + trimester addition: +0 kcal (1st) · +340 kcal (2nd) · +450 kcal (3rd)

Energy needs are estimated from pre-pregnancy weight. The IOM additions apply on top of your usual TDEE for a healthy singleton pregnancy.

Worked example

  1. 1

    A 28-year-old woman, 165 cm and 65 kg before pregnancy.

  2. 2

    BMR = 10 × 65 + 6.25 × 165 − 5 × 28 − 161 ≈ 1430 kcal/day.

  3. 3

    Lightly active (×1.375): TDEE ≈ 1966 kcal/day.

  4. 4

    In her second trimester: ≈ 1966 + 340 ≈ 2306 kcal/day.

How your calorie needs change

Your resultCategoryWhat it means
First trimester+0 kcal/dayIn early pregnancy, total energy needs are roughly unchanged for most women — eat to your appetite and add nothing extra.
Second trimester+340 kcal/dayFetal growth accelerates. The IOM guidance suggests adding about 340 kcal/day on top of your usual needs.
Third trimester+450 kcal/dayThe biggest increase — the baby gains weight fastest now, and the IOM recommendation rises to about 450 kcal/day extra.
Twins or moreHigher needsMultiple pregnancies require distinctly higher intake. This calculator is for single pregnancies — speak with your provider for multiples.

Institute of Medicine (2009) energy-intake estimates on top of your usual pre-pregnancy TDEE for a healthy singleton pregnancy.

Frequently asked questions

Sources & further reading

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This calculator provides general estimates for informational purposes only and is not medical advice. For personal guidance, consult a qualified healthcare provider.