Baby growth tracker for weight, length and family records

Clinic visits and home scales produce numbers that are easy to misplace. Luna lets you log weight and length measurements into the same family timeline as feeds and sleep, then review them later, including via the growth summary API used by the app.

Luna does not plot official centile diagnoses, tell you whether growth is “normal,” or replace your qualified health professional chart. Bring concerns about weight or length to a qualified professional.

What you can record

• Weight and length in metric or imperial at entry (log_measurement); API stores canonical kg/cm as noted on /developers.
• Measurement history through app views / GET /api/vega/measurements (weight and length events).
• Milestones and firsts as notes on the timeline (log_note, remember for durable preferences): organisational memories, not developmental assessments.
• Activity / first-year style logging by keeping everyday events and notes together (feeds, sleeps, solids) rather than a separate silo.

How to keep measurements tidy

1. After a weigh-in, log the number while you still remember the unit.
2. Add a note if the measurement happened at clinic vs home scale.
3. Share the family log so the other parent sees the same figures.
4. Use export if you want a copy for your own records (Privacy).
5. For interpretation, use your health professional, not Luna Plus, not the connector.

Searches folded into this pillar

Growth chart, weight tracker, length tracker, milestone tracker, first year tracker and activity tracker doorways all pointed at “keep growing-up records in one place.” This pillar is that home. Charts you may see in-product are for organising your entries; they are not a substitute for clinical growth charts.

Measurements as timeline events

Weight and length entries work best when they are ordinary events with dates, not a separate anxiety spreadsheet. Log the number after clinic or home weigh-ins, keep units consistent between caregivers as much as possible, and let both parents see the same history.

The developers’ portal notes that volumes and measurements have canonical storage units for the API even when display units differ by family region settings. Parents using the app simply enter what the scale shows; you do not need to know the API.

Milestones and “first year” memories

Many doorway pages talked about milestones and first-year tracking. Luna’s honest version: use notes for first smiles, first foods, first visits, and keep measurements for numbers. That combination covers the emotional and practical record without pretending Luna performs developmental screening.

If a qualified health professional gives you a concern to watch, store factual notes you are comfortable sharing with invited caregivers, or keep sensitive clinical detail out of the shared log entirely.

What “growth chart” means here

Searchers often want a chart. Luna may help you review logged measurements over time via the measurements history. That is still your data listed, not an endorsement that Luna replaces official growth charts used in UK clinics. Bring the printout or clinic record to professionals when decisions are needed.

Working alongside clinic visits

Many UK families weigh in at home between qualified health professional appointments. Luna can store those interim numbers so you are not hunting through photos of the scale. When you attend clinic, you can read back what you logged, without asking Luna whether the curve is “ok.”

If region/units are set for your family (UK/US style settings appear in profile tooling on the connector as get_child_profile), display preferences stay consistent for caregivers on the same log. That reduces the classic mix-up where one parent thinks in kilograms and the other in pounds.

Keep expectations modest: Luna is a journal for measurements, not a growth clinic in your pocket.

Want calm answers from your own log?

Free Luna already keeps the shared tracker and the assistant connector. Luna Plus (£3.99/mo) adds Ask Luna: answers and summaries grounded in what your family has actually logged, in the app or through a connected assistant such as Meta Muse or Claude.

Plus can help you ask log-grounded questions about what was recorded recently. It still will not interpret centiles or give medical growth advice.

See Luna Plus →

Safety boundary

Luna is for organising baby logs and routine summaries. It is not a medical device and does not diagnose, treat, assess allergies, set doses, or replace a qualified health professional or emergency services. For symptoms, medication, allergy or treatment decisions, use a qualified health professional or urgent care route. Read our Safety page for the full boundary.

Related Luna guides

• Baby tracker app
• Baby notes app
• Baby feeding tracker
• Weaning & allergen tracker
• Shared baby tracker
• Baby routine tracker