Weight Gain Result
Enter values and calculate.
Calculator Inputs
Growth Chart
The chart plots birth, previous, and latest weights when available, plus average daily gain across the measured interval.
Formula Used
Weight gain = Latest weight − Previous weight
Average daily gain = (Latest weight − Previous weight) ÷ Number of days between weigh-ins
Average weekly gain = Average daily gain × 7
Percent change = [(Latest weight − Previous weight) ÷ Previous weight] × 100
Total change from birth = Latest weight − Birth weight
This calculator converts every entry to grams first, performs the calculations, then displays values in your selected unit and grams per day for growth rate comparisons.
How to Use This Calculator
- Choose the weight unit that matches your scale readings.
- Enter the previous and latest weigh dates.
- Input both measured weights exactly as recorded.
- Add birth weight if you want total change from birth.
- Optionally enter diapers, feeding pattern, and notes.
- Press Calculate Weight Gain to view the result above the form.
- Review the chart, metrics, and interpretation.
- Download CSV or PDF if you want a saved summary.
Example Data Table
| Baby | Birth Date | Previous Date | Latest Date | Previous Weight | Latest Weight | Average Daily Gain |
|---|---|---|---|---|---|---|
| Baby A | 2026-02-01 | 2026-02-15 | 2026-02-22 | 3.95 kg | 4.16 kg | 30 g/day |
| Baby B | 2026-01-10 | 2026-03-01 | 2026-03-15 | 5.32 kg | 5.58 kg | 18.6 g/day |
| Baby C | 2025-11-18 | 2026-03-05 | 2026-03-19 | 7.12 kg | 7.24 kg | 8.6 g/day |
FAQs
1. What does this calculator estimate?
It estimates weight change between two weigh-ins for a breastfed baby. It shows total gain, daily gain, weekly gain, percent change, and optional change from birth weight.
2. Why does the tool convert everything to grams?
Grams make rate calculations more precise, especially for infant growth. The page still displays the entered unit for readability, while grams per day remain the standard comparison figure.
3. Can I use pounds or ounces?
Yes. The calculator accepts grams, kilograms, pounds, and ounces. It converts the values behind the scenes and returns the growth summary in your selected unit.
4. What if my baby lost weight?
The calculator will show a negative change and a negative daily rate. That does not explain the cause. Contact your pediatrician or lactation consultant promptly if you are concerned.
5. Does this replace a growth chart visit?
No. It helps organize measurements, but it does not replace clinical assessment, feeding observation, dehydration checks, or growth chart interpretation by a qualified professional.
6. How often should I weigh my baby?
That depends on age, recent feeding history, and your clinician’s advice. Frequent weighing without context can increase stress, so follow a plan given by your care team.
7. Why is there a feeding pattern field?
It lets you save extra context in exported reports. Feeding pattern details may be useful when discussing weight trends with a pediatrician or lactation consultant.
8. When should I seek help quickly?
Seek timely medical advice for poor feeding, lethargy, fewer wet diapers, fever, jaundice concerns, ongoing weight loss, or any situation that feels worrying to you.