New Ballard Score Calculator for Gestational Age
Ballard score calculator for gestational age: estimate newborn gestational age in weeks from neuromuscular + physical maturity signs or a known total score.
Quick answer
The New Ballard score calculator converts bedside maturity scoring into an estimated gestational age. Enter the neuromuscular and physical maturity subtotals, or enter the total Ballard score directly, then review the estimated weeks alongside obstetric dating and clinical context.
Clinical disclaimer
Total score is used if provided; otherwise, the calculator sums the two subtotals.
How to use the New Ballard score calculator
- Score the newborn's six neuromuscular signs and six physical maturity signs with a validated New Ballard scoring sheet.
- Enter the neuromuscular subtotal and physical maturity subtotal, or enter the total Ballard score if it is already calculated.
- Review the estimated gestational age in weeks and document the exam timing, source scores, and relevant clinical context.
How the score works
The New Ballard Score evaluates six neuromuscular signs and six physical maturity signs. Each item is scored, the subtotals are summed, and the total score is converted to an estimated gestational age.
- Total score range: -10 to 50.
- Estimated gestational age is calculated as GA (weeks) = 24 + 0.4 × total score.
- Use an official scoring sheet to select the correct sign scores before entering values here.
Inputs and output
| Field | What it means | Use note |
|---|---|---|
| Neuromuscular subtotal | Posture, square window, arm recoil, popliteal angle, scarf sign, and heel-to-ear maturity signs. | Enter this when scoring domains separately. |
| Physical maturity subtotal | Skin, lanugo, plantar surface, breast, eye/ear, and genital maturity signs. | Use the validated score sheet, not a visual guess. |
| Estimated gestational age | Approximate gestational age in weeks from the total New Ballard score. | Interpret with obstetric dating, newborn status, and local protocol. |
Clinical notes
- Use bedside scoring when obstetric dating is uncertain or to corroborate other gestational age data.
- Accurate scoring depends on technique and newborn stability; trend with other clinical information.
- Document timing of the exam and any factors that may affect tone or appearance.
Related calculators
References
Frequently asked questions
It estimates gestational age by scoring neuromuscular and physical maturity signs in a newborn. The total score is converted to weeks of gestation.
A common bedside estimate is gestational age in weeks = 24 + 0.4 × total New Ballard score, after summing neuromuscular and physical maturity signs.
No. If you already have a total score from a scoring sheet, enter the total directly. Otherwise, enter the neuromuscular and physical subtotals and the calculator will sum them.
The New Ballard Score expanded the original scoring system to include very preterm infants, but accuracy still depends on proper technique and timing.
No. Use it as a bedside estimate when obstetric dating is uncertain or to corroborate other gestational age data.