Most healthy newborns gain about 150–210 grams per week in the first 3 months, then about 100–140 grams per week from 3 to 6 months.
Newborn weight can feel like a puzzle in the first days. The scale dips, then climbs. We talk about grams per week because tiny bodies change fast, and small numbers add up quickly.
Right after birth, many babies shed fluid and drop 5–10% of birth weight. Most return to birth weight by day 10 to day 14, then the steady climb begins. From there, weekly gain paints a clear picture of growth.
Newborn Weight Gain Per Week In Grams — Ranges And Real-World Patterns
During months 0–3, average gain lands near 20–30 grams per day. That works out to roughly 150–210 grams each week. Past 3 months, the pace eases. Between months 3–6, many babies gain around 100–140 grams per week. From 6–12 months, weekly gain often slides closer to 70–100 grams as rolling, crawling, and standing burn more energy.
These are ranges, not quotas. One week might look light, the next week leaps ahead. Watch the overall curve, not single weigh-ins.
Ounce-To-Gram Cheat
- 30 g ≈ 1 oz
- 90 g ≈ 3 oz
- 150 g ≈ 5 oz
- 180 g ≈ 6 oz
- 210 g ≈ 7½ oz
| Age Window | Typical Gain (g/day; g/week) | Notes |
|---|---|---|
| Birth–Day 3 | Initial loss | Fluid shift; 5–10% drop is common |
| Day 3–14 | 20–30 g/day; ~140–210 g/week | Back to birth weight by day 10–14 |
| Weeks 2–4 | 20–30 g/day; ~150–210 g/week | Frequent feeds; growth spurt around week 3 |
| Months 1–3 | 20–30 g/day; ~150–210 g/week | Fastest phase for many babies |
| Months 3–6 | 15–20 g/day; ~100–140 g/week | Pace eases |
| Months 6–12 | 10–15 g/day; ~70–100 g/week | Mobility rises; solids join milk |
What Affects Weekly Gain
Feeding pattern: Frequent, effective milk transfer drives growth. Many babies take 8–12 feeds in 24 hours during the early weeks.
Latch and transfer: A deep latch, rhythmic swallowing, and brief pauses point to good intake. Clicking sounds, painful feeds, or long sessions without swallowing can slow gain.
Gestation and birth weight: Late preterm babies and those with lower birth weight may have a different glide path.
Growth spurts: Short bursts around week 3 and week 6 can cluster feeds and shake up the weekly total.
Sleep and output: Six or more wet diapers after the first week, plus regular stools, often align with steady gain.
Scale and technique: Weigh on the same scale, with a dry diaper, at a similar time of day to limit noise.
How To Track Weight Without Stress
Pick a single scale when you can. Different scales can report slightly different numbers. Aim for the same setup each time: same clothing, same time window, and a dry diaper.
Plot gains on trusted charts. The World Health Organization offers weight velocity standards that show expected increments by age. You can view the tables on the WHO weight velocity page.
When you want plain language guidance, the AAP’s family resource explains typical daily gains and the early drop after birth. See the HealthyChildren overview. Use these as guides, while your clinic team tracks the full pattern across visits.
Week One Through Week Four: What Many Parents See
Week one: feeds are frequent and short. Weight falls, then levels out by the end of the week as milk volume rises.
Week two: weight usually passes the birth mark. Feeds lengthen, swallowing sounds become steady, diapers pick up.
Week three: a growth spurt often arrives. Cluster feeds in the evening are common, and the weekly gain can jump.
Week four: babies settle into their own rhythm. Some gain near the top of the band, others sit closer to the middle.
When Growth Surges Hit
Watch for hunger cues that stack closer together: waking sooner, rooting, hand-to-mouth, and strong sucking. Respond with on-cue feeds. Short, frequent sessions across a day can add up to a strong week even when no single feed looks huge.
A calm burp and a brief pause between sides can reset a baby who gets drowsy mid-feed. Skin-to-skin time helps many newborns stay alert enough to finish the job.
Preterm And Smaller Newborns
Late preterm babies (born at 34–36 weeks) may tire faster at the breast or bottle. They often need shorter gaps between sessions and more help with latch and positioning.
Babies with lower birth weight may gain in smaller steps at first. Close follow-up with weight checks keeps the plan suited to the baby.
Reading Growth Charts
Percentiles and z-scores are tools, not grades. A baby who rides the 15th percentile line week after week is growing well.
A one-time dot that sits lower than a sibling’s dot says little by itself. Trends across visits tell the story.
Crossing several lines down over a short span can flag a feeding issue or illness. Crossing up may just reflect a catch-up phase.
When Numbers Jump Up Fast
A big week can follow a growth spurt, a cluster of longer night feeds, or a switch to more efficient feeding. Active babies often spread that gain into length soon after.
If bottle volumes creep up without hunger cues, watch for gulping and shortness of breath. Paced bottle steps keep intake baby-led.
How Length And Head Size Fit In
Weight, length, and head size move together over time. If weight is surging while length and head size flatten, the team may look closer at feed volumes and timing.
If all three points are climbing along the same track, the pattern makes sense and the weekly weight swings matter less.
Feeding Tips That Support Steady Gain
Offer both breasts at each feed in the early weeks. Switch sides when swallowing slows.
Use breast compressions during active sucking to keep milk moving.
Wake a sleepy newborn for feeds if long gaps appear. A common rhythm is every 2–3 hours by day and 3–4 hours by night at first.
For bottle sessions, try paced bottle feeding so the baby can pause and breathe.
Track wet diapers and stools. Output trends often mirror intake.
Protect overnight feeds when possible. Night milk volumes and hormones often help milk supply.
Sample Weekly Checks In Grams
Pick one day each week to weigh at home, then repeat the next week at the same time. Subtract last week’s number from this week’s number to get the weekly gain.
Here’s a quick walk-through: If your baby weighed 3,600 g last week and 3,760 g today, that is a 160 g week. That sits inside the common 150–210 g band for months 0–3. Next week might land higher or lower, and the chart tells the story over time.
Myths And Misreads To Avoid
“Daily gain must be the same.” Daily swings happen. Check the week and the curve, not single days.
“Formula always gains faster.” Patterns vary. Feeding skill, volume, timing, and baby size all play parts.
“Sleepers don’t grow.” Many sleepy babies gain well with frequent, effective feeds.
“Solids push weight up fast.” Before age one, milk still carries most calories. Solids start as practice, then ramp up.
“One slow week means trouble.” A soft week can follow a wet diaper mistake, a cold, or a growth spurt reshuffle.
When Weight Gain Needs A Check
Call your clinic if any red flags below match your week. These signs do not diagnose a problem on their own, but they tell you to get timely help.
| Sign | What It May Mean | Next Step |
|---|---|---|
| Not back to birth weight by day 14 | Feeding or transfer issue | Book a feed and weight check |
| <30 g/day in months 0–3 | Insufficient intake or illness | Assess latch, schedule, and output |
| <20 g/day in months 3–6 | Falling intake or rising activity | Review feed volume and cues |
| Fewer than 6 wet diapers after week 1 | Dehydration risk | Same-day assessment |
| Long, sleepy feeds with poor swallowing | Low transfer | Hands-on latch support |
| Sudden drop across percentiles | Pattern shift that needs context | Growth chart review |
Breast And Bottle: Small Tweaks That Help
Start feeds when the first cues appear. Waiting for strong crying can shorten a session and lower transfer.
Hold baby close, tummy to tummy, chin tipped up. A wide open mouth, more areola in the mouth on the lower side, and lips flanged out keep the latch deep.
If you pump, confirm flange fit and gentle settings. Comfort often yields more milk than high suction.
For bottle sessions, try a slow-flow nipple and keep the bottle level, not vertical. Pause every few swallows to allow breathing and satiety signals to catch up.
Burp between sides or at mid-bottle. Gas can mimic hunger and lead to extra volume that the baby doesn’t need.
Close the day with skin-to-skin and a calm, dim room. Many babies feed best when distractions fade.
When To Seek Same-Day Care
- No wet diaper in 6 hours or sunken soft spot
- Breathing that looks labored during feeds
- Green vomit, blood in stool, or repeated forceful spit-ups
- Jaundice that deepens after day 4
- Listless behavior and weak sucking
The Bottom Line On Weekly Gain
In the first 3 months, many newborns add 150–210 grams per week. In months 3–6, a common band is 100–140 grams per week. After that, the pace softens again. What matters most is a steady climb on the chart with feeds that feel calm and effective.
If numbers drift below the ranges listed in the table, or birth weight is not back by the end of week two, schedule a prompt check. Early adjustments make a big difference and bring peace to feed times. Keep tracking each week.