Pregnancy Weight Calculator
Determines the healthy weight that can be safely put on during the 40 weeks of pregnancy based on several details.
Below the form there is in depth information on how the weight guidelines are calculated.
The pregnancy weight calculator determines the amount of weight that can be put on in a healthy manner during the 40 week pregnancy.
The calculation can be applied to both single and twin pregnancies.
In case the pregnancy week is specified, information about the weight range for that week is also given separately.
The two tables provided below, present the total amount of weight to be put on during pregnancy in lbs respectively kg, by considering the weight before pregnancy and the type of pregnancy.
■ Single pregnancy:
| 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 |
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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.
About the pregnancy weight calculator
This calculator provides a healthy weight gain schedule for the entire pregnancy, based on the individual characteristics such as weight before pregnancy, height and type of pregnancy.
During the first step of the calculation, the body mass index is computed based on weight and height in order to determine the category the subject is in.
This category, along with the type of pregnancy (single or twins) will then inform the health guidelines for normal pregnancy weight gain that are to be used in the specified case.
The result provided consists in the BMI category, the total amount of acceptable weight gain, the weight range for the specified week of pregnancy and a table with the whole 40 week weight schedule, from week 0 of conception to week 44 of the pregnancy due date.
The body mass index offers information about the general health status based on weight and gain. The BMI categories and values used in the above calculator are:
| Category of weight | BMI range |
| Underweight | <18.5 |
| Normal weight | 18.5 and 25 |
| Overweight | 25 and 29 |
| Obese | >30 |
Pregnancy weight gain guidelines
The amount of gained weight during the first trimester of pregnancy (the first 3 months) is around 4 lbs (2 kg).
During the second and third trimester of pregnancy, approximately 1 lbs (500 g) will be added weekly. This is a guideline only, as in practice, pregnant women with bigger weights tend to put on less than 1 lbs per week of pregnancy.
The following two tables, indicate the total amount of weight to be put on during pregnancy in both lbs and kg, depending on the weight before pregnancy (seen from BMI category) and on type of pregnancy.
■ Single pregnancy:
| 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 |
References
1. Institute of Medicine. (2009) Weight Gain During Pregnancy: Re-examining the Guidelines.
2. Rasmussen KM, Catalano PM, Yaktinec AL. New guidelines for weight gain during pregnancy: what obstetrician/gynecologists should know. Curr Opin Obstet Gynecol. 2009; 21(6): 521–526.
Specialty: Obstetrics Gynecology
System: Reproductive
Objective: Determination
Type: Calculator
No. Of Variables: 4
Article By: Denise Nedea
Published On: April 3, 2017 · 08:45 AM
Last Checked: April 3, 2017
Next Review: April 3, 2023