Pregnancy Macro Calculator for Every Trimester
Enter your age, height, pre-pregnancy weight, trimester and activity level. The calculator returns a daily calorie target with protein, carbohydrate and fat grams, adjusted for the stage you are at.
Fill out the form to see your personalized results
Your macro and water intake recommendations will appear here
How the numbers are worked out
Maintenance comes first. The Mifflin-St Jeor equation gives your resting burn from weight, height and age, then an activity factor between 1.2 and 1.9 turns it into the calories you use in a normal day.
The trimester adds to that total. The US Dietary Guidelines and ACOG put the extra need at nothing in the first trimester, about 340 calories a day in the second, and about 452 calories a day in the third. The calculator adds the right one for you, so a woman maintaining at 2,000 calories eats about 2,340 in the second trimester.
Protein rises with pregnancy too, to roughly 1.1 grams per kilogram of body weight, which is around 70 to 100 g a day for most women. Fat holds near 30 percent of calories, and carbohydrate takes the remainder with a floor of 175 g a day, the amount recommended to supply the baby's brain with glucose.
These are population averages. Your obstetrician or midwife knows your case, and their numbers override anything on this page, particularly with twins, gestational diabetes or a pre-pregnancy weight outside the normal range.
Who this is for
Women who have been told to "eat a bit more" and want to know how much more, in food rather than in principle. The second trimester figure of 340 calories is roughly a sandwich and a glass of milk, not a second dinner.
It also helps anyone whose appetite has stopped matching their needs. First trimester nausea often means eating less exactly when the habit needs building, and the third trimester can bring hunger that runs well past the actual requirement.
Pregnancy calories by trimester
First trimester needs no extra calories at all, which surprises most people. The baby is tiny and the cost of building it is small. Eat at maintenance and focus on folate, iron and keeping food down.
Second trimester adds about 340 calories a day. Growth accelerates and appetite usually returns, so this is the easiest stage to hit the target without thinking about it.
Third trimester adds about 452 calories a day. Stomach capacity drops as the baby takes up room, so most women find four or five smaller meals easier than three larger ones.
Protein and iron during pregnancy
Protein at 1.1 g per kilogram is a real increase, not a rounding difference. Spread it across the day rather than loading dinner, since a 25 to 30 g portion at each meal is used better than 80 g in one sitting.
Iron is the other number worth watching, at 27 mg a day against 18 mg before pregnancy. It is hard to reach from food alone, which is why prenatal vitamins carry it. Vitamin C at the same meal improves absorption from plant sources.
Track it in NutriScan
Seeing the day add up matters more here than in most plans, because both undereating and steady overeating carry consequences. NutriScan logs meals from a photo, your voice, a barcode or typed text, then shows calories, protein, carbs and fat against the targets from this page.
The free plan gives you 5 photo scans a week, unlimited manual logging, water tracking and the fasting timer. Water is worth tracking through pregnancy, since needs rise to around 2.3 litres a day. Premium removes the scan cap and costs about $59 a year.
Frequently asked questions
How many extra calories do I need in each trimester of pregnancy?
None in the first trimester, about 340 extra calories a day in the second, and about 452 extra calories a day in the third, per the US Dietary Guidelines and ACOG. The calculator adds the right figure to your maintenance calories for you.
How much protein should I eat during pregnancy?
Around 1.1 grams per kilogram of body weight, which lands near 70 to 100 g a day for most women. Spread it across the day in portions of 25 to 30 g rather than loading it all at dinner.
Is this a pregnancy calorie calculator as well as a macro calculator?
Yes. Set your trimester and it returns your daily calorie target along with protein, carbohydrate and fat grams, so one page covers both.
Is there a minimum carbohydrate intake in pregnancy?
Yes, 175 g a day is the recommended floor, higher than the 130 g for adults who are not pregnant. The extra supplies glucose to the baby's brain, which is why very low carb diets are not advised during pregnancy.
Can I use this if I am vegetarian or vegan?
Yes. The targets are the same whatever you eat. Iron, vitamin B12 and omega 3 need more attention on a plant based diet, so talk to your midwife or doctor about supplements alongside the food.
Should I use this if I have gestational diabetes?
Treat it as background reading only. Gestational diabetes comes with carbohydrate targets per meal set by your care team, and those override anything here.
Can I keep using it as my pregnancy progresses?
Yes. Update your trimester and your weight and the targets move with them. In the app you can log meals, adjust portions and see the daily totals against the new numbers.
Related calculators
- Macro calculator for a standard split outside pregnancy
- TDEE calculator for the maintenance number the trimester adds to
- Protein intake calculator for daily grams and a per meal split
- Calorie calculator for logging a meal from a photo or a line of text
- NutriScan for pregnancy for how the app handles trimester targets