Health
Pregnancy Weight Gain Calculator by Week
Estimate recommended pregnancy weight gain by week using your height, pre-pregnancy weight, BMI category, and current pregnancy week.
Pregnancy Weight Gain Calculator
Estimate recommended pregnancy weight gain based on pre-pregnancy BMI, height, weight, and current pregnancy week.
This calculator uses pre-pregnancy BMI to estimate a general pregnancy weight gain range. It is for educational reference only.
Direct answer
11.5 kg – 16.0 kg
Recommended total pregnancy weight gain range based on pre-pregnancy BMI.
Pre-pregnancy BMI
22.0
BMI category
Normal weight
Recommended by week 20
4.5 kg – 4.5 kg
Recommended gain range
The bars below compare your estimated total pregnancy weight gain range with the estimated range for your current pregnancy week.
Save and export multiple pregnancy weight gain results
Save each pregnancy weight gain estimate, select the rows you want, then export the selected results as CSV or TXT.
Page guide
On this page
Jump to the calculator explanation, BMI table, weekly reference, usage guide, and FAQ.
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How this pregnancy weight gain calculator works
This calculator first estimates pre-pregnancy BMI from height and pre-pregnancy weight. It then matches that BMI to a recommended pregnancy weight gain range.
It also estimates a simple pregnancy weight gain by week range based on the current week you enter. This weekly number is a reference, not a strict target.
Pregnancy weight gain can vary across trimesters and from person to person, so use this result as a general guide and discuss personal questions with a qualified healthcare professional.
Formula notes
BMI formula
BMI = Weight (kg) ÷ Height² (m²)
Recommended pregnancy weight gain ranges depend on the BMI category before pregnancy. The weekly estimate is calculated from the total range and the selected pregnancy week.
What is a pregnancy weight gain calculator?
A pregnancy weight gain calculator estimates a recommended weight gain range during pregnancy based on your height, pre-pregnancy weight, and current pregnancy week. It helps turn BMI and week information into a clear estimate.
Many people look for pregnancy weight gain by week, recommended pregnancy weight gain, and pregnancy weight gain by BMI because the expected range depends on starting body size and stage of pregnancy.
Pregnancy weight gain by BMI category
Recommended pregnancy weight gain usually depends on pre-pregnancy BMI category. In general, a lower starting BMI is linked with a higher recommended gain range, while a higher starting BMI is linked with a lower recommended gain range.
| BMI category | Pre-pregnancy BMI | Recommended total gain |
|---|---|---|
| Underweight | Below 18.5 | 12.5–18.0 kg |
| Normal weight | 18.5–24.9 | 11.5–16.0 kg |
| Overweight | 25.0–29.9 | 7.0–11.5 kg |
| Obesity | 30.0 and above | 5.0–9.0 kg |
Pregnancy weight gain by week reference table
The table below shows a simple pregnancy weight gain by week reference using your current height and pre-pregnancy weight. These values are estimates rather than exact targets for every week.
| Week | Stage | Estimated recommended gain |
|---|---|---|
| 13 | End of first trimester | 0.5 kg – 2.0 kg |
| 20 | Mid-pregnancy | 4.5 kg – 4.5 kg |
| 30 | Third trimester | 8.0 kg – 10.3 kg |
| 40 | Full term reference | 11.5 kg – 16.0 kg |
How to use this pregnancy weight gain calculator
Enter your height, pre-pregnancy weight, and current pregnancy week. The calculator estimates your pre-pregnancy BMI, identifies a BMI category, and shows both a total recommended gain range and a current-week reference range.
This can help you understand pregnancy weight gain by week, compare your current progress with a general range, and learn how BMI affects expected weight gain during pregnancy.
Why pregnancy weight gain matters
Pregnancy weight gain is one of many measurements used during prenatal care. It can relate to nutrition, fetal growth, and general pregnancy monitoring.
Real pregnancy weight gain is not perfectly linear. Some weeks may show little change, while others may show faster change. That is why this calculator is best used as an educational reference instead of a strict target.
Pregnancy weight gain calculator FAQ
How much weight should I gain during pregnancy?
Recommended pregnancy weight gain depends mainly on pre-pregnancy BMI. People who begin pregnancy at a lower BMI are usually advised to gain more, while people who begin at a higher BMI are usually advised to gain less.
How much pregnancy weight gain is recommended by week?
Pregnancy weight gain by week is usually estimated from the total recommended gain range and the current week of pregnancy. It is a rough reference rather than an exact weekly target.
Why does BMI affect recommended pregnancy weight gain?
Pre-pregnancy BMI affects recommended weight gain because nutritional needs and pregnancy-related risks can differ depending on starting body size.
Is pregnancy weight gain the same in every trimester?
No. Weight gain is often lower during early pregnancy and may become more consistent later. Trimester-by-trimester patterns can vary widely.
Is the weekly estimate exact?
No. It is a simplified estimate intended for general reference. Actual weight gain can vary across weeks and trimesters.
Is this pregnancy weight gain calculator medical advice?
No. It is an educational estimate and should not replace prenatal care or advice from a healthcare professional.
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