Pregnancy Weight Gain Calculator
Use this pregnancy weight gain calculator to compare your current gain with a broad week-by-week estimate based on pre-pregnancy BMI.
Pregnancy weight gain targets vary by individual health, pregnancy type, and clinical guidance. Use this as a planning estimate only.
How it's calculated
Recommended range is estimated from pre-pregnancy BMI category and pregnancy week
The calculator uses common singleton-pregnancy reference ranges by starting BMI category, then estimates progress through the second and third trimesters. Clinical advice should always take priority.
What your result means
| Category | Range | What it means |
|---|---|---|
| Underweight | 12.5-18 kg | A higher full-term gain range is commonly referenced for lower starting BMI. |
| Normal weight | 11.5-16 kg | A middle reference range for many singleton pregnancies. |
| Overweight | 7-11.5 kg | A lower full-term range is often referenced for higher starting BMI. |
| Obesity | 5-9 kg | A lower full-term range may be recommended, with individual clinical context. |
How pregnancy weight gain is interpreted
Recommended gain depends partly on pre-pregnancy BMI, but also on pregnancy type, nausea, fluid shifts, fetal growth, and clinician guidance.
Why week matters
Weight gain is usually not linear across pregnancy. This calculator gives a simple progress estimate rather than a strict weekly rule.
Use with clinical guidance
Pregnancy nutrition and weight changes are personal. Use this page for planning questions to discuss with your clinician, not as a diagnosis.
Frequently asked questions
How much weight should I gain during pregnancy?
It depends on pre-pregnancy BMI, pregnancy type, and medical guidance. This calculator estimates broad singleton-pregnancy reference ranges.
Is pregnancy weight gain linear?
No. Many people gain little in the first trimester and more steadily later, but individual patterns vary.
What if I am outside the estimated range?
Do not panic. Fluid, nausea, appetite, and fetal growth all affect weight. Bring the trend to your clinician.
Does this work for twins?
No. Twin and higher-order pregnancies use different guidance and need clinician-specific advice.