Use our Pregnancy Weight Gain Calculator to estimate a healthy weight gain range by week based on your pre-pregnancy BMI and whether you’re expecting one baby or twins. The tool converts between metric and imperial units, helps you understand targets for each trimester, and compares your current progress with evidence-based recommendations.
Why pregnancy weight gain matters
Healthy, steady weight gain supports your baby’s growth, reduces the risk of complications, and can make postpartum recovery easier. Recommendations vary depending on your starting body mass index (BMI) and whether you’re carrying a single baby or twins. The calculator aligns with widely cited guidelines to estimate total and weekly targets.
How the Pregnancy Weight Gain Calculator works
- You enter your pre-pregnancy weight and height to estimate BMI.
- You indicate your current week of pregnancy and current weight.
- The calculator returns: your BMI category, a recommended total weight gain range, an estimated cumulative gain target for your current week, and your current progress compared with that target.
Typical guideline ranges
For singleton pregnancies, total weight gain recommendations generally increase as BMI decreases. Underweight parents-to-be may be advised to gain more overall, while those with higher BMI may have lower total targets. For twin pregnancies, recommended totals are higher, and weekly gains in the second and third trimesters are typically faster.
What’s included in your result
- BMI and BMI category from your pre-pregnancy weight and height.
- Suggested total weight gain range for your pregnancy type (singleton or twins).
- Estimated healthy gain by your current week, including a typical first-trimester cushion and a per-week pace for the second and third trimesters.
- Your current gain compared with the recommended range (below, within, or above), shown in both kilograms and pounds.
Tips for using the calculator
- Enter your height in either centimeters or feet plus inches, not both.
- Use the same unit system for pre-pregnancy and current weights.
- Track progress by revisiting every few weeks and updating your current weight and week of pregnancy.
- Discuss results with your healthcare provider, especially if you have twins, medical conditions, or questions about appetite, nausea, or fluid retention.
Beyond the numbers
The calculator offers estimates, not medical diagnoses. Individual circumstances vary: morning sickness, activity level, and medical history can influence healthy weight gain patterns. Hydration and balanced nutrition are just as important as the number on the scale. If your results fall outside the suggested range, consider discussing them with your provider to tailor a plan that fits your needs.
Healthy habits that support your target
- Eat balanced meals with whole grains, lean proteins, healthy fats, fruits, and vegetables.
- Prioritize steady, nutrient-dense snacks if you experience nausea or early fullness.
- Stay active as recommended by your provider (for example, walking or prenatal yoga).
- Sleep and stress management support appetite and overall well-being.
When to seek guidance
If you experience sudden, rapid changes in weight, persistent vomiting, swelling, or any concerning symptoms, contact your healthcare provider. For twin pregnancies and for those starting pregnancy underweight or with higher BMI, personalized care is especially helpful.
Use the Pregnancy Weight Gain Calculator regularly to stay informed. Shared with your provider, it can be a helpful conversation starter about nutrition, activity, and a healthy pace of gain throughout pregnancy.