Pregnancy Weight Gain Calculator
Offers guidance on how much weight should be gained safely during pregnancy (be it singular or multiple).
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Steps on how to print your input & results:
1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.
2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.
Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.
Pregnancy weight gain guidelines
Health regulations on pregnancy weight depend on the weight category of the expectant mother at the start of the pregnancy and of how many babies are carried. This calculator uses such guidance to recommend the total weight gain as well as breaks it down for each of the three trimesters.
Below are two charts that summarize the total weight gain in lbs and kgs, depending on the mother’s body mass index and whether the pregnancy is multiple.
Pregnancy with one baby
| Weight situation BMI | Lbs to put on | Kg to put on |
| Underweight | 28 – 40 | 13 – 18 |
| Normal weight | 25 – 35 | 11 – 16 |
| Overweight | 15 – 25 | 7 – 11 |
| Obese | 11 – 20 | 5 – 9 |
Pregnancy with twins
| Weight situation BMI | Lbs to put on | Kg to put on |
| Underweight | 28 – 40 | 13 – 18 |
| Normal weight | 37 – 54 | 17 – 25 |
| Overweight | 31 – 50 | 14 – 23 |
| Obese | 25 – 42 | 11 – 19 |
The impact of weight at the start of pregnancy
The weight category of the expectant mother, one of the starting points of weight recommendations, is expressed based on body mass index (BMI) values. BMI is an indicator of weight in relation to height and reflects whether a person is underweight, of normal weight, overweight or obese:
| BMI range | Category of weight |
| < 18.5 | Underweight |
| 18.5 and 25 | Normal weight |
| 25 and 29 | Overweight |
| > 30 | Obese |
If the expectant mother is classed as underweight, there are higher risks associated with the pregnancy (i.e. risk of miscarriage or fetal complications) than in the case of a normal weight mother.
If the expectant mother is overweight or obese, weight during pregnancy must be monitored as to not exceed guidelines, because there is an increased risk of early labour and premature birth.
References
Wylie L. (2005) Essential anatomy and physiology in maternity care (2nd ed.) Edinburgh: Churchill Livingstone.
Bateson P. (2001) Fetal experience and good adult design. International Journal of Epidemiology 30 (5): 928–934
Institute of Medicine. (2009) Weight Gain During Pregnancy: Reexamining the Guidelines.
Specialty: Obstetrics Gynecology
System: Reproductive
Article By: Denise Nedea
Published On: April 14, 2020 · 12:00 AM
Last Checked: April 14, 2020
Next Review: April 14, 2025