Most pregnant women gain 10 to 12.5 kg (22 to 28 lb), with most of it after week 20 (NHS). Use our pregnancy weight gain estimator to see your own week-by-week range.
How Much Weight Should You Gain During Pregnancy?
According to the NHS, most pregnant women gain 10 to 12.5 kg (22 to 28 lb), with most of it after week 20. While using the pregnancy weight gain calculator, it's essential to use BMI-based recommendations.
The recognized international BMI-based recommendations (Body Mass Index) are the following:
| Pre-Pregnancy BMI | Recommended Weight Gain |
| Underweight (<18.5) | 12.5โ18 kg (28โ40 lb) |
| Normal Weight (18.5 โ 24.9) | 11.5โ16 kg (25โ35 lb) |
| Overweight (25 โ 29.9) | 7โ11.5 kg (15โ25 lb) |
| Obese (30+) | 5โ9 kg (11โ20 lb) |
Weight gain during pregnancy is normal and healthy; however unchecked weight gain can lead to significant complexities and health issues.
How Much Weight Should You Gain in Each Trimester?
Most people gain only 0.5 to 2 kg (1.1 to 4.4 lb) in the first trimester. After that, the guide is a steady weekly gain based on your BMI before pregnancy: about 0.35 to 0.5 kg (0.8 to 1 lb) a week for a healthy BMI, and less for higher BMIs.
After the first trimester, the weekly guide is about 0.44 to 0.58 kg (1 to 1.3 lb) if you were underweight, 0.35 to 0.5 kg (0.8 to 1 lb) at a healthy weight, 0.23 to 0.33 kg (0.5 to 0.7 lb) if overweight, and 0.17 to 0.27 kg (0.4 to 0.6 lb) if obese.
Use our pregnancy weight gain estimator to see your own week-by-week range.
Is "Eating for Two" True?
No. The NHS says you'll probably feel hungrier than usual, but you don't need to "eat for two", even with twins or triplets. Pregnancy isn't the time to diet, either. The aim is a balanced diet and steady weight gain within the range for your BMI, guided by your midwife or doctor.
Source: NHS, Have a healthy diet in pregnancy.
When to Talk to Your Midwife or Doctor About Weight Gain
Gaining much faster or slower than your range, sudden swelling of the face, hands or feet, or weight loss after the first trimester. Gaining too much raises the risk of gestational diabetes and pre-eclampsia, and gaining too little is linked with premature birth and low birth weight (NHS).
What Affects Pregnancy Weight Gain?
- Various women face morning sickness, nausea, and vomiting during their first trimester of pregnancy. As a consequence, such women either lose weight or gain a little.
- Your weight scale can change significantly owing to an increase in blood volume and fluid retention in the body.
- Moreover, you will face fatigue frequently after any physical activity. Constant physical activity can result in pelvic pain for expectant women.
- Medical restrictions may affect your weight gain patterns.
- If you are carrying twins or triplets, you will gain more weight as compared to normal pregnancy.
Conclusion
A pregnancy weight gain calculator is a valuable tool for pregnant women who want to track their weight gain and health during this phase. These tools provide accurate tracking and nutrition guidance to women according to their experiences.
Every pregnancy is unique, hence, your results may vary according to your genetics, nausea, fluid retention, lifestyle, and medical conditions. Therefore, it's best to take care of yourself, eat healthy, and consult your physician while using the pregnancy weight gain calculator.
The due date calculator estimates how far along the pregnancy is. After birth, the breastfeeding calorie calculator estimates extra calories while nursing.
Frequently Asked Questions (FAQs)
Why Should I Use a Pregnancy Weight Gain Calculator?
A pregnancy weight gain calculator helps with tracking weight, comparing weight gain or loss with medically recommended ranges, details about concerns related to weight during pregnancy, and discussing that tracking with a midwife or doctor.
How much weight should I gain during pregnancy?
It depends on your BMI before pregnancy: 11.5โ16 kg (25โ35 lb) for a healthy BMI, more if underweight, and less if overweight or obese. The NHS says most women gain 10โ12.5 kg.
Is it normal to lose weight in the first trimester?
It can be, especially with nausea and vomiting. If you can't keep food or fluids down, contact your midwife or doctor.
Sources
- NHS, Weight gain in pregnancy
- NHS, Have a healthy diet in pregnancy
- CDC, Weight Gain During Pregnancy
- Institute of Medicine and National Research Council, Weight Gain During Pregnancy: Reexamining the Guidelines, 2009
Last updated: October 17, 2026