Pregnancy Calorie Calculator
Enter your age, height, pre-pregnancy weight, activity level and trimester to get your daily calories and TDEE for each trimester.
Your daily calories this trimester
2,638calories a day
Your maintenance plus 340 calories for the second trimester.
In NutriScan, open Profile, then Modify Macros, and type 2,638 as your calorie goal. Each meal you log by photo, voice or text counts down from it.
Your calories in each trimester
| Trimester | Extra a day | calories a day |
|---|---|---|
| First, weeks 1 to 12 | +0 | 2,298 |
| Second, weeks 13 to 26 | +340 | 2,638 |
| Third, week 27 onward | +452 | 2,750 |
An estimate for one baby: Mifflin-St Jeor maintenance plus the Institute of Medicine trimester additions. Twins, gestational diabetes or a weight plan from your doctor change the number, so check it with your doctor or midwife.
How the pregnancy calorie calculator works
It runs two steps. The first is your maintenance, also called TDEE. The Mifflin-St Jeor equation gives the calories you burn at rest:
BMR = 10 x weight in kg + 6.25 x height in cm - 5 x age - 161
That BMR is multiplied by an activity factor: 1.2 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, 1.9 extra active. The result is what you needed each day before pregnancy.
The second step adds the trimester figure from the Institute of Medicine's Dietary Reference Intakes (2005), which the Dietary Guidelines for Americans 2020 to 2025 repeat:
| Trimester | Weeks | Extra calories a day |
|---|---|---|
| First | 1 to 12 | 0 |
| Second | 13 to 26 | 340 |
| Third | 27 onward | 452 |
Use your pre-pregnancy weight. The additions already cover the growth of the pregnancy, so your current weight would count it twice.
These are averages for a healthy pregnancy with one baby. This page is information, not medical advice. Your doctor or midwife may set a different number, and theirs is the one to follow, especially with twins, gestational diabetes or a pre-pregnancy BMI under 18.5 or over 25.
Worked example
A 30 year old woman, 165 cm, 65 kg before pregnancy, moderately active:
- BMR: 10 x 65 + 6.25 x 165 - 5 x 30 - 161 = 1,370 calories
- TDEE: 1,370 x 1.55 = 2,124 calories a day
- First trimester: 2,124 + 0 = 2,124 calories a day
- Second trimester: 2,124 + 340 = 2,464 calories a day
- Third trimester: 2,124 + 452 = 2,576 calories a day
The second trimester increase of 340 calories is about one peanut butter sandwich. Eating for two would mean 2,124 extra calories a day, six times that.
Pregnancy TDEE: why the first trimester adds nothing
A pregnancy TDEE calculator gives the same answer as this page, because pregnancy TDEE is your normal TDEE plus the trimester addition. In the first 12 weeks the baby is still under 100 g and costs very little energy, so the addition is zero. From week 13 your blood volume, the placenta and the baby all grow faster, and the 340 and 452 calorie figures cover that.
If nausea keeps you under your number in the first trimester, tell your doctor or midwife and eat what stays down. The target matters more from the second trimester.
Healthy weight gain alongside the calories
The Institute of Medicine's 2009 guidelines, which ACOG follows, tie total weight gain to your pre-pregnancy BMI. Your calorie target is the daily input, and this range is how your care team checks it over months.
| Pre-pregnancy BMI | Total gain, one baby |
|---|---|
| Under 18.5 | 12.5 to 18 kg (28 to 40 lb) |
| 18.5 to 24.9 | 11.5 to 16 kg (25 to 35 lb) |
| 25 to 29.9 | 7 to 11.5 kg (15 to 25 lb) |
| 30 and over | 5 to 9 kg (11 to 20 lb) |
If your gain runs above or below your range for several weeks, raise it at your next appointment before changing what you eat.
Track your pregnancy calories in NutriScan
A daily number only helps if you can see the day against it. In NutriScan you pick the Pregnancy goal and your trimester during setup, then log meals from a photo, your voice, a barcode or a typed line. The home screen shows calories, protein, carbs and fat eaten and what is left.
To use the number from this page, open Profile, then Modify Macros, and type it in as your calorie goal. Change it when you move to the next trimester.
The free plan gives you 5 scans a week and water tracking. Premium removes the scan cap and costs about $59 a year. The app has passed 150k downloads and holds a 4.6 star rating.
Frequently asked questions
How many calories should I eat while pregnant?
Your pre-pregnancy maintenance calories in the first trimester, about 340 more a day in the second and about 452 more a day in the third. For a moderately active 30 year old woman at 65 kg and 165 cm that is 2,124, then 2,464, then 2,576 calories a day. The figures come from the Institute of Medicine and apply to one baby.
How do I calculate my TDEE during pregnancy?
Work out your TDEE the usual way from your pre-pregnancy weight: Mifflin-St Jeor BMR multiplied by an activity factor from 1.2 to 1.9. Then add 0, 340 or 452 calories for the first, second or third trimester. The calculator on this page does both steps and shows your BMR and TDEE next to the pregnancy total.
Do I need extra calories in the first trimester?
No. The Institute of Medicine sets the first trimester addition at zero, because the baby is still very small. Eat at your maintenance level and put the attention on folate, iron and keeping food down.
Is there a pregnancy calorie calculator by week?
Calorie guidance changes by trimester, not by week. Weeks 1 to 12 use your maintenance number, weeks 13 to 26 add 340 calories a day, and week 27 onward adds 452. Pick the trimester your current week falls in and the calculator applies the right figure.
Should I enter my current weight or my pre-pregnancy weight?
Your pre-pregnancy weight. The trimester additions were worked out on top of pre-pregnancy energy needs, so entering your current weight counts part of the pregnancy twice.
How many calories do I need if I am pregnant with twins?
More than this calculator shows, and there is no single official figure. The 340 and 452 calorie additions are for one baby. With twins or more, ask your obstetrician or midwife for a personal target.
Related calculators
- Pregnancy macro calculator to split these calories into protein, carbs and fat
- TDEE calculator for maintenance calories outside pregnancy
- Protein intake calculator for daily grams and a per meal split
- PCOS macro calculator for a split weighted for insulin resistance
- Diabetes macro calculator for carb-aware targets
- NutriScan for pregnancy for how the app tracks meals through each trimester