Is My Baby Gaining Weight Normally?
Weight gain is one of the clearest signals of how well a baby is feeding and growing. This baby weight gain calculator compares your baby's actual weight gain since birth against typical age-based expected ranges, so you can see at a glance whether things are tracking normally.
💡 Typical Weekly Gain Guidelines
Most babies regain their birth weight by around 2 weeks, then gain roughly 5-7 oz/week for the first 3 months, 3-5 oz/week from 3-6 months, and 2-3 oz/week from 6-12 months.
Typical Weight Gain by Age
| Age | Typical Weekly Gain |
|---|---|
| 0-2 weeks | Regains birth weight, modest initial gain |
| 2 weeks - 3 months | ~5-7 oz (155-200 g) per week |
| 3-6 months | ~3-5 oz (85-140 g) per week |
| 6-12 months | ~2-3 oz (55-85 g) per week |
How This Calculator Works
The tool starts from your baby's birth weight and adds up the typical expected weekly gain for every week up to their current age, producing an expected weight range (±15%). It then compares that range with the weight you entered and calculates your baby's actual average weekly gain.
Weight gain naturally varies week to week — growth spurts, illness, and feeding changes can all cause temporary swings. This calculator is a general guide, not a medical diagnosis. Always discuss growth concerns with your pediatrician, who tracks your baby's full growth curve over time.