Worked example: Pregnancy Weight Gain Calculator
Normal BMI range. This fixed reference example shows one complete scenario; the interactive results above use your current inputs.
View the example inputs
- Measurement units
- Metric
- Height
- 170 cm
- Pre-pregnancy weight
- 65 kg
- Current weight
- 75 kg
| Calculated quantity | Example result |
|---|---|
| Pre-pregnancy BMI | 22.49 kg/m² |
| Observed weight change | 10 kg |
| Total-pregnancy reference lower gain | 11.3 kg |
| Total-pregnancy reference upper gain | 15.9 kg |
| Total-pregnancy reference lower gain | 25 lb |
| Total-pregnancy reference upper gain | 35 lb |
Understanding calendar-based pregnancy and cycle estimates
Know which date is being estimated
The first day of a menstrual period, an estimated ovulation date, a conception estimate and a due date refer to different events. A due-date calculation using a regular-cycle assumption does not observe fertilization or predict the actual delivery day.
Cycle length and dating conventions affect the calendar arithmetic. The page explains whether a result starts from a menstrual date or works backward from an existing due date. Use the same date convention when comparing the result with another source.
Use the right population and clinical context
Calendar windows cannot confirm ovulation, establish paternity or provide reliable contraception. Irregular cycles and clinical ultrasound findings can change dating. Pregnancy weight references also depend on their stated population, such as a singleton pregnancy and pre-pregnancy BMI.
The worked example shows the formula’s arithmetic. Its dates and reference ranges are illustrative inputs, not an assessment of an individual pregnancy. For care decisions, use dating and targets established with a prenatal clinician.
Formula and calculation method
CDC singleton total-gain ranges: BMI<18.5: 28–40 lb; 18.5–<25: 25–35 lb; 25–<30: 15–25 lb; BMI≥30: 11–20 lb.
Observed gain=current weight−pre-pregnancy weight. These are total-pregnancy ranges, not week-specific targets.
Scope and Limitations
- Singleton pregnancy only; not for multiple gestation or individual clinical treatment. Compare timing and personal needs with a prenatal clinician.
Reference Sources
Frequently asked questions
How does this calculator work?
CDC singleton total-gain ranges: BMI<18.5: 28–40 lb; 18.5–<25: 25–35 lb; 25–<30: 15–25 lb; BMI≥30: 11–20 lb.
What assumptions should I check?
Singleton pregnancy only; not for multiple gestation or individual clinical treatment. Compare timing and personal needs with a prenatal clinician. Observed gain=current weight−pre-pregnancy weight. These are total-pregnancy ranges, not week-specific targets.
Can I save or print this calculation?
Use Copy link with inputs to reproduce the scenario, Download results for a text record, or Print. Where a schedule is shown, its CSV download includes every row.
What happens when I change measurement units?
The linked unit selector converts the existing measurement so it represents the same physical quantity. Entering a different number after switching units changes the underlying input. The result’s own units are shown beside its value.