Enter your pre-pregnancy weight, height, age, activity level and trimester to see an estimate of your daily energy needs and a macronutrient breakdown.
Extra calories are usually not needed in the first trimester: daily energy needs are the same as before pregnancy. In the second and third trimesters, needs depend on your age, height, pre-pregnancy weight, week of pregnancy, activity level and pre-pregnancy BMI (UpToDate, 2026). The extra energy cost of a pregnancy has been estimated at about 50,000 kcal in total (UpToDate, 2026). Energy intake is a key nutritional factor in a baby's birth weight, but more than needed leads to excess weight gain.
The best way to tell whether your energy intake is adequate is to follow your weight gain; you can use the pregnancy weight gain calculator. NICE also stresses that there is no need to “eat for two” in pregnancy (NICE NG247, 2025).
Energy requirement references were updated in 2023 using doubly labeled water measurements. In this approach, a different energy deposition factor is used in the second and third trimesters depending on pre-pregnancy BMI (UpToDate, 2026):
| Pre-pregnancy BMI | Energy deposition factor |
|---|---|
| Underweight | +300 kcal/day |
| Normal | +200 kcal/day |
| Overweight | +150 kcal/day |
| Obese | −50 kcal/day |
This factor is not the whole requirement; it is one component added to the need calculated from age, height, weight, week of pregnancy and activity. You can find your BMI category with the BMI calculator.
The tool first estimates the energy you use at rest (basal metabolic rate) with the Mifflin-St Jeor equation and multiplies it by a factor for your chosen activity level; the result is your estimated daily need based on your pre-pregnancy weight. It does not add a fixed pregnancy extra: in the first trimester it notes that no extra is needed, and in the second and third trimesters it calculates your BMI from the values you entered and shows, as a note, the energy deposition factor used for that BMI group in the current approach. This factor is part of a separate equation that also includes the week of pregnancy and activity, so the result is approximate (UpToDate, 2026).
The tool splits the estimated need into 50% carbohydrate, 20% protein and 30% fat. These shares sit within the ranges the Dietary Guidelines for Americans give for pregnancy: carbohydrate 45–65%, protein 10–35%, fat 20–35% (UpToDate, 2026).
| Nutrient | Daily recommendation in pregnancy | When not pregnant |
|---|---|---|
| Protein (2nd and 3rd trimesters) | 71 g (1.1 g/kg) | 46 g (0.8 g/kg) |
| Carbohydrate | 175 g | 130 g |
| Fiber | 28–36 g | — |
| Fat | 20–35% of energy; saturated fat below 10% | — |
| Fluid (from drinks) | About 2.3 liters (about 10 cups) | — |
| Caffeine | Below 200–300 mg | — |
Source: UpToDate, 2026. Protein powders and high-protein supplements are not recommended; lean meat, poultry, eggs, seafood, beans, peas, lentils, nuts and seeds are good protein sources. Highly processed meats are not recommended. For food lists, see the pregnancy nutrition guide.
Your weight gain is the best guide to whether the estimate fits you (UpToDate, 2026).
Usually not. In the first trimester, daily energy needs are the same as before pregnancy (UpToDate, 2026).
In the current approach the extra depends on pre-pregnancy BMI: an energy deposition factor of +300 kcal/day for underweight, +200 for normal weight, +150 for overweight and −50 for obese people. Total needs also depend on age, height, weight, week of pregnancy and activity.
The recommended amount in the second and third trimesters is 71 g a day (about 1.1 g/kg), compared with 46 g when not pregnant. Protein powders and high-protein supplements are not recommended.
The recommendation for fluid from drinks is about 2.3 liters a day, or about 10 cups (UpToDate, 2026).
Keep caffeine below 200–300 mg a day.
No. NICE states that there is no need to “eat for two” and, apart from avoiding specific foods and drinks, no special diet is needed in pregnancy, but eating a variety of foods every day is important (NICE NG247, 2025).
Last updated: .