Pediatric Weight Estimation (APLS) — free guideline decision tool
This tool estimates a child's weight from age using the APLS/Luscombe formulas when weighing is not possible.
Open guideline tool →Guideline-based
Implements the decision logic from published clinical guidelines.
Runs in your browser
No installation. Enter the patient's values and get a guideline recommendation instantly.
Data stays local
Nothing is uploaded. Results are for licensed clinicians only.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Age unit | Months (0–12 months) |
|---|---|
| Age | 3 |
→Estimated weight5.5kg
- Formula：0.5 × months + 4
| Age unit | Years (1–12 years) |
|---|---|
| Age | 3 |
→Estimated weight14kg
- Formula：2 × years + 8
Common questions
What is Pediatric Weight Estimation (APLS)?
This tool estimates a child's weight from age using the APLS/Luscombe formulas when weighing is not possible.
How is Pediatric Weight Estimation (APLS) calculated? What is the core formula?
Months: 0.5 × months + 4. Years 1–5: 2 × years + 8. Years 6–12: 3 × years + 7.
When is Pediatric Weight Estimation (APLS) used?
Use in emergencies to derive a working weight for drug dosing, equipment sizing, and defibrillation energy.
What are the key clinical points for Pediatric Weight Estimation (APLS)?
The estimate is for emergencies only — when weighing is possible the measured weight always takes precedence. (original synthesis · not guideline verbatim) Deviation is large in obese or developmentally atypical children. Different formulas apply to infants versus older children, so the correct age band must be selected.
What are the limits and cautions when using Pediatric Weight Estimation (APLS)?
For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
How is Pediatric Weight Estimation (APLS) calculated in practice? Can you show a worked example?
Inputs: Age unit Months (0–12 months), Age 3 → Result: Estimated weight 5.5 kg（Formula: 0.5 × months + 4） Inputs: Age unit Years (1–12 years), Age 3 → Result: Estimated weight 14 kg（Formula: 2 × years + 8）
Run Pediatric Weight Estimation (APLS) now
This tool estimates a child's weight from age using the APLS/Luscombe formulas when weighing is not possible.
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
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