The calm baby tracker
The calm way to remember everything.
Feeds, sleep, diapers, pumping — one gentle place, synced for your whole family.
Coming soon
Scan to download
Point your phone camera at the code to install the Android app.
Free during early access · Early birds keep premium features free forever
Track
Log in two taps
One-handed timers for nursing, bottles, sleep, and diapers. NFC tags for your changing table — tap and go.
Share
Everyone's in sync
Partner, grandparent, nanny — all see the same live data. No more "when did the baby last eat?" texts at 3 AM.
Understand
See the pattern
Trends, AAP-style guidance, and WHO growth curves turn scattered logs into a calm, clear picture.
Grounded in research
Predictions built on published pediatric science.
Not vague guesses: Moonbelly models how your baby's stomach empties, learns your family's day-and-night rhythm, and personalizes everything to your baby's age, sex, and weight.
Milk remaining, right now
A continuous intake-and-emptying model tracks how much of the last feed is still in the stomach, so you know roughly how much more to offer.
Next feed, from your rhythm
Learns your baby’s own day-part rhythm — longer stretches at night, cluster feeds in the evening — instead of one flat average.
Personalized to your baby
Weight (measured or WHO median by age and sex), milk type, and feed duration all shape every estimate.
Model basis: Cavell, J Pediatr 1981 (gastric half-emptying 48 min human milk / 78 min formula) · van den Driessche et al., JPGN 1999 (47 vs 65 min) · Kent et al. 2006 (breastfeed intake) · WHO Child Growth Standards 2006. Estimates are reference-only and are never medical advice.
Built for 3 AM
A soft night-light, not a dashboard.
Moonbelly is quiet by design. Muted colors, big tap targets, and a dark theme that glows gently when the rest of the house is asleep.
One account. One source of truth.
Invite the people who help you care. Parents, grandparents, and nannies all log into the same shared timeline — so everyone knows what happened, and no one repeats the question.
- ·Roles for parent, grandparent, nanny, and more
- ·See who logged each event
- ·Live updates the moment something is saved
Bottle · 90 ml
2 min ago · Dad
Sleep · 1h 20m
ongoing · Mom
Diaper · wet
4 min ago · Nana
Checkup-ready
Bring your data to the pediatrician.
Generate a clean PDF report of feeding, sleep, and growth — plotted against WHO curves — and share it at your next visit.
Your family's data is yours.
What we do
- Store only what you choose to log
- Encrypt your data in transit and at rest
- Let you export everything, anytime
- Delete your account on request — instantly
What we never do
- Sell your data, to anyone, ever
- Show ads
- Share with third parties for marketing
- Profile or compare your baby to others
"The night feeds got easier the moment my husband could see them too."
"I brought the growth report to our 4-month checkup. The doctor loved it."
"Finally a tracker that doesn’t feel like a spreadsheet at 3 AM."
Questions
Can I track multiple babies?+
Yes. One account can track multiple children, each with their own timeline, growth curve, and color — perfect for twins or siblings.
Does it work offline?+
Yes. You log on your phone even without a signal; everything syncs to the cloud (and to your family) as soon as you reconnect.
Can I see my data on the web?+
Yes. Sign in from any browser to review trends, print a growth report, or share the screen with your pediatrician — no app install needed.
Is it really free?+
Free during early access, and better than that: accounts created during early access keep every premium feature free forever. If paid tiers arrive later, you will not be gated out of anything. We will also never sell your data or show ads.
Can I delete my data?+
Always. Export everything as a file, or delete your account entirely — instantly, no questions, from Settings.
Can I import from another baby tracker?+
Import from common formats is on the roadmap. If you have a specific app in mind, join the waitlist and tell us — we prioritize what you need.
Start tracking tonight.
Free during early access, and early birds keep every premium feature free forever. Your data stays yours — exportable and deletable anytime.
Coming soonScan to download
Point your phone camera at the code to install the Android app.