How many calories do you need when pregnant?
Pregnancy increases your energy needs, but by much less than most people think. The U.S. Institute of Medicine recommends no extra calories in the first trimester, about 340 extra kcal a day in the second trimester and about 452 extra kcal a day in the third. That is roughly a small extra meal or two healthy snacks — not double portions. This pregnancy calorie calculator starts from your own pre-pregnancy needs, so the result fits your body and lifestyle.
How the calculator works
- Your pre-pregnancy resting needs are estimated with the Mifflin-St Jeor equation (women: 10 × kg + 6.25 × cm − 5 × age − 161).
- That is multiplied by your activity level to give your usual daily needs.
- The trimester amount is added: +0, +340 or +452 kcal.
Example: a 30-year-old, 160 cm and 60 kg before pregnancy, lightly active: 600 + 1,000 − 150 − 161 = 1,289 kcal × 1.375 ≈ 1,772 kcal. In the second trimester she needs about 2,112 kcal, and in the third about 2,224 kcal.
Pregnancy calories: too low, right and too high
| Intake | Level | What it means |
|---|---|---|
| Well below your target, or under 1,800 kcal in the 2nd–3rd trimester | Too low | Risk of poor weight gain, low birth weight and nutrient gaps (iron, folate, iodine, calcium) |
| Within about ±100–200 kcal of your target | On track | Supports healthy weight gain — check with the pregnancy weight gain calculator |
| Regularly 500+ kcal above target (“eating for two”) | Too high | Excess weight gain, higher risk of gestational diabetes, high blood pressure and a large baby |
Benefits of eating the right amount
- Healthy growth for your baby and lower risk of complications.
- Healthy weight gain that is easier to lose after birth.
- Steadier blood sugar and lower risk of gestational diabetes.
- More energy and fewer cravings when meals are balanced and regular.
Health warnings
- Do not diet or fast to lose weight in pregnancy unless your obstetrician advises it.
- Twins, teenage pregnancy, underweight, diabetes and other conditions need individual advice.
- Severe vomiting with weight loss (hyperemesis gravidarum) needs medical treatment.
- Take a prenatal supplement with folic acid, iron, iodine and vitamin D as advised by your doctor. Avoid high-dose vitamin A supplements.
- If you plan to fast in Ramadan while pregnant, speak to your doctor first.
What to eat with your extra calories
Choose protein (eggs, dal, chicken, fish low in mercury), wholegrains, vegetables, fruit, dairy or calcium-fortified alternatives, and healthy fats. Good snacks: Greek yoghurt with fruit, a handful of nuts and dates, hummus with vegetables, or a cheese and salad sandwich on wholegrain bread. Read our trimester guides — second trimester and third trimester — and our page on gestational diabetes.
Frequently asked questions
Do I need to eat for two when pregnant?
No. You need no extra calories in the first trimester, about 340 extra a day in the second and about 450 extra a day in the third. That is roughly one or two healthy snacks, not double portions.
How many calories should I eat in the first trimester?
Usually the same as before pregnancy. Focus on food quality, folic acid and small frequent meals if you feel sick.
How many calories should I eat in the third trimester?
About 450 kcal a day more than before pregnancy for most women. The calculator above gives a personal number.
Should I count calories during pregnancy?
Most women do not need to count strictly. Use these numbers as a guide, eat regular balanced meals and let your doctor track your weight gain.
Do I need more calories with twins?
Yes, women expecting twins usually need more energy and protein, but needs vary a lot. Ask your obstetrician or a dietitian for a personal target.
Sources
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids. 2005 (pregnancy EER).
- Institute of Medicine and National Research Council. Weight Gain During Pregnancy: Reexamining the Guidelines. 2009.
- EFSA. Dietary Reference Values for water. 2010.