Pregnancy Calorie Needs Calculator
Enter your age, height, prepregnancy weight, current weight, gestational week, and activity level. The calculator uses the 2023 DRI pregnancy energy equation and shows the BMI-based adjustment behind the result.
Estimated daily calorie need (kcal/day)2,750
- Energy-deposition adjustment (kcal/day)
- 200
- Prepregnancy BMI
- 23.88
- Prepregnancy BMI category
- Normal weight
- Weight gained so far (kg)
- 5
- Recommended total pregnancy gain
- 25-35 lb
- Recommended weekly gain in trimesters 2-3
- 0.8-1.0 lb/week
Weeks 1-13 use the adult female 2023 DRI EER equation because first-trimester energy deposition is treated as negligible.
The IOM weight-gain ranges shown here are for singleton pregnancies.
The negative deposition term for obesity is part of the population equation, not advice to intentionally lose weight during pregnancy.
How to use this calculator
- Enter your current age, height, prepregnancy weight, and current weight.
- Enter the completed gestational week of the pregnancy.
- Choose the activity category that best reflects your current routine.
- Review the calorie estimate with the BMI category, weight-gain context, and assumptions.
How the pregnancy calorie estimate is calculated
This calculator uses the 2023 Dietary Reference Intakes estimated energy requirement equations for adult pregnancy. The inputs are current age in years, height in centimeters, current body weight in kilograms, completed gestational week, current activity category, and prepregnancy BMI. The result is rounded to the nearest 10 kcal/day because the equation is a population estimate, not a meal prescription.
Prepregnancy BMI is calculated first:
BMI = prepregnancy weight kg / (height m)^2
For weeks 1-13, the calculator uses the adult female equation for the selected activity level. For example, the low active equation is:
EER = 575.77 - 7.01A + 6.60H + 12.14W
For week 14 and later, it uses the pregnancy equation. The low active pregnancy equation is:
EER = 693.35 - 2.04A + 5.73H + 10.20W + 9.16G + D
- A is age in years.
- H is height in centimeters.
- W is current weight in kilograms.
- G is completed gestational weeks.
- D is the energy-deposition adjustment selected from prepregnancy BMI.
How BMI changes the second and third trimester result
The 2023 equation uses current weight, but prepregnancy BMI still matters because it selects the energy-deposition term after the first trimester. The adjustment is 300 kcal/day for underweight BMI, 200 for normal weight, 150 for overweight, and -50 for obesity. A BMI exactly at 18.5, 25.0, or 30.0 enters the higher category.
The calculator also shows the Institute of Medicine singleton pregnancy weight-gain ranges for the same BMI category: 28-40 lb for underweight, 25-35 lb for normal weight, 15-25 lb for overweight, and 11-20 lb for obesity. The weekly ranges shown apply to trimesters 2 and 3. They are context for discussing the trend with a clinician, not a diagnosis of whether the current gain is right or wrong.
What moves the estimate most
Activity category and current body weight usually move the result more than gestational week from one week to the next. The week term still matters because it increases the pregnancy equation by 9.16 kcal/day for each completed week. The first trimester can look lower because the calculator is intentionally using the adult equation until week 14.
What this calculator leaves out
This calculator is for adult singleton pregnancy estimates. It does not calculate needs for twins or higher-order multiples, adolescents, hyperemesis, diabetes, eating disorders, bariatric surgery, metabolic disease, prescribed activity restriction, or a clinician-directed nutrition plan. It also does not judge diet quality, protein intake, micronutrients, fetal growth, or whether intentional weight loss is appropriate. The -50 kcal/day term for obesity is part of the DRI model and should not be read as advice to diet during pregnancy.
Worked example
Suppose a 30-year-old is 165 cm tall, weighed 65 kg before pregnancy, weighs 70 kg now, is at 28 completed weeks, and chooses low active. Prepregnancy BMI is 65 / 1.65^2 = 23.88, so the normal-weight deposition term after the first trimester is 200 kcal/day.
The low active pregnancy equation gives 693.35 - 2.04*30 + 5.73*165 + 10.20*70 + 9.16*28 + 200 = 2748.08 kcal/day. Rounded to the nearest 10, the calculator shows 2,750 kcal/day. Weight gained so far is 70 - 65 = 5 kg, and the displayed singleton pregnancy gain range for this BMI category is 25-35 lb total with 0.8-1.0 lb/week in trimesters 2 and 3.
Common questions
How many extra calories are needed in each trimester?
This calculator does not add one fixed number by trimester. Weeks 1-13 use the adult female DRI equation because first-trimester energy deposition is treated as negligible. From week 14 onward, the 2023 pregnancy equation includes exact gestational week, current weight, activity, and a prepregnancy-BMI deposition term.
Why does this differ from a BMR or TDEE calculator?
Most BMR or TDEE calculators estimate nonpregnant energy use and then add a fixed pregnancy amount. The DRI pregnancy equation is specific to pregnancy and uses current weight, gestational week, activity category, and prepregnancy BMI. That makes it more specific, but it is still an estimate with individual variation.
Why does the updated equation use current weight?
The 2023 DRI pregnancy equations use current weight because total energy expenditure changes with body size during pregnancy. Prepregnancy weight is still used to calculate BMI, which selects the energy-deposition adjustment and the weight-gain reference ranges.
What activity level should I choose?
Choose inactive if daily movement is limited and there is little purposeful activity. Choose low active for light routine movement, active for regular moderate activity, and very active for a high activity load. If activity is restricted for medical reasons, use the restricted level recommended by your care team rather than trying to average across categories.
Should calories change if weight gain is above or below the range?
The weight-gain range is context, not an automatic instruction to increase or decrease calories. Weight trend, symptoms, fetal growth, fluid shifts, diet quality, and clinical conditions all matter. Review unexpected gain or loss with an obstetric clinician or registered dietitian.
Can this calculator be used for twins or triplets?
No. The equations and IOM ranges shown here are for singleton pregnancy. Twin and higher-order multiple pregnancies need individualized targets, so this calculator should not be used for those cases.