Quick-access pediatric calculators

⚠️ Pedia Pocket is a clinical decision-support tool for qualified healthcare professionals. It provides calculations and guideline summaries for reference only and does not replace clinical judgment, local protocols, specialist advice, or direct patient assessment. Always verify results before clinical use.

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📋 About & Disclaimer ▾

Fluids

Maintenance, deficits & bolus

💧

Maintenance Fluids

Holliday-Segar method

▾

Weight

Daily requirement —

Hourly rate —

Multiplier

Formula


First 10 kg → 100 mL/kg/day
Next 10 kg → 50 mL/kg/day
Each kg beyond 20 → 20 mL/kg/day


Hourly = Daily ÷ 24

Reference Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics. 1957;19(5):823–832.

⚡

Fluid Bolus

Resuscitation volume

▾

Weight

Bolus Dose

Bolus volume —

Dose used —

Formula Volume (mL) = Weight (kg) × Dose (mL/kg)

Reference APLS / PALS Guidelines. Standard isotonic crystalloid bolus is typically 10–20 mL/kg. Adjust based on clinical context.

🌡️

Dehydration Deficit

Fluid deficit calculator

▾

Weight

Degree of Dehydration

Fluid deficit —

+ Maintenance (24h) —

Total 24h fluid —

Hourly rate —

Formula


Deficit (mL) = Weight (kg) × % dehydration × 10
Total = Deficit + 24h Maintenance
Hourly = Total ÷ 24

Reference Holliday-Segar for maintenance. Dehydration percentages per WHO/AAP clinical assessment guidelines. Replace deficit over 24–48h per clinical judgment.

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Glucose Infusion Rate (GIR)

mg/kg/min from IV dextrose infusion

▾

Dextrose Concentration

e.g. D5W = 5%, D10W = 10%

Infusion Rate

mL/hr

Weight

GIR —

Target GIR in neonates: 4–8 mg/kg/min. Hypoglycaemia management may require up to 12 mg/kg/min.

Formula


GIR (mg/kg/min) =
  Dextrose% × Rate (mL/hr) × 1000
  ÷ (Weight (kg) × 60 × 100)

Simplified: (D% × rate) ÷ (weight × 6)

Reference Rozance PJ, Hay WW. Hypoglycemia in newborn infants. Biol Neonate. 2006;90(2):74–86.

Standard neonatal & paediatric practice for glucose delivery rate monitoring during IV dextrose therapy.

Neonatal

Jaundice, weight loss & corrected age

⚖️

Neonatal Weight Loss

% loss from birth weight

▾

Birth Weight

Current Weight

Weight lost —

% weight loss —

Formula


% Loss = ((Birth wt - Current wt) / Birth wt) × 100

Normal physiologic loss: up to 7–10% in first week.

Reference AAP Newborn Nursery Guidelines. Neonates typically regain birth weight by 10–14 days.

🗓️

Corrected Age

For preterm infants

▾

Date of Birth

Gestational Age at Birth

weeks

Chronological age —

Prematurity correction —

Corrected age —

Formula


Weeks premature = 40 - GA at birth
Corrected age = Chronological age - weeks premature

Reference AAP Committee on Fetus and Newborn. Corrected age used for developmental assessment until 2–3 years in preterm infants (<37 weeks GA).

🌅

Neonatal Jaundice

AAP 2022 · ≥35 weeks GA

▾

GA at birth

Postnatal age

hrs

Total Serum Bilirubin (TSB)

µmol/L ⇄

Tap the unit to switch between µmol/L and mg/dL

Neurotoxicity Risk Factors

Additional neurotoxicity risk factors: albumin <3.0 g/dL, isoimmune hemolytic disease/DAT+, G6PD deficiency or other hemolysis, sepsis, or significant clinical instability in previous 24h. GA is already handled by the nomogram.

⚠️ Uses exact AAP 2022 Supplemental Table 1–4 values by completed hour. Verify clinically, especially if <24h, hemolysis, illness, or direct bilirubin >50% of TSB.

Method — AAP 2022 Uses the exact AAP 2022 Supplemental Table 1–4 numeric values for phototherapy and exchange transfusion thresholds, stratified by completed gestational age, completed postnatal hour, and additional neurotoxicity risk factors. Applies to infants ≥35 weeks GA, age 1–336 hours.


Inputs:
  GA: 35, 36, 37, 38, 39, or ≥40 weeks
  Age: postnatal hours, 1–336
  Risk: additional neurotoxicity risk factors yes/no

Outputs:
  Phototherapy threshold
  Escalation threshold = exchange threshold − 2 mg/dL
  Exchange transfusion threshold

Important:
  Use total serum bilirubin (TSB).
  Do not subtract direct/conjugated bilirubin.
  Infants <24h at/above threshold need urgent hemolysis evaluation.

Reference Kemper AR, Newman TB, Slaughter JL, et al. Clinical Practice Guideline Revision: Management of Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation. Pediatrics. 2022;150(3):e2022058859.

Replaces: AAP 2004 guideline (Pediatrics 2004;114:297-316).

Growth & Development

Growth charts (WHO · CDC · Saudi) · BSA · Developmental milestones

📈

Growth Chart Plotter

Plot on WHO / CDC / Saudi charts

▾

Sex

Age

yrs ⇄

Tap unit to switch between years / months

Weight

Height/Length

Head Circ.

Chart Type

Reference

International: WHO (0–2y) + CDC (2–20y) · Saudi: LMS 0–18y for WFA/HFA/BMI

References WHO Child Growth Standards (0–5 years): de Onis M et al. WHO Multicentre Growth Reference Study. 2006.

CDC Growth Charts (2–20 years): Kuczmarski RJ et al. Vital Health Stat. 2002. Note: CDC charts start at 2 years — use WHO for children under 2.

Saudi Growth Charts: Shaik SA, El Mouzan MI, Al Salloum AA, Al Herbish AS. Ann Saudi Med. 2016;36(1):2–6 (0–5y LMS parameters); El Mouzan MI et al. Ann Saudi Med. 2016;36(4):265–268 (5–18y LMS parameters for weight, height and BMI); El Mouzan MI et al. Saudi Med J. 2007;28(10):1555–1568 (fallback charts). Endorsed by the Saudi Council for Health Services.

🧮

BSA Calculator

Body Surface Area

▾

Weight

Height

Formula

Body Surface Area —

Formulas


Mosteller: sqrt(Ht x Wt / 3600)
DuBois: 0.007184 x Ht^0.725 x Wt^0.425
Haycock: 0.024265 x Ht^0.3964 x Wt^0.5378

References Mosteller RD. Simplified calculation of body surface area. N Engl J Med. 1987;317(17):1098.

DuBois D, DuBois EF. A formula to estimate the approximate surface area if height and weight be known. Arch Intern Med. 1916;17(6):863–871.

Haycock GB, Schwartz GJ, Wisotsky DH. Geometric method for measuring body surface area. J Pediatr. 1978;93(1):62–66.

🧒

Milestones Tracker

Enter age · 2 weeks – 6 years

▾

Age unit

Age

How to use

Enter the child's age in weeks, months, or years. Three milestone cards appear:

● Current — always visible and highlighted. Milestones expected by the entered age.
✓ Already expected — tap to expand. Skills from the previous band that should already be mastered.
→ Developing now — tap to expand. Skills from the next band that are emerging.

Below the milestone cards, two red-flag cards are shown:

🚩 Age-specific red flags — from AAP Table 5 for the current age group.
🚩 Universal red flags — apply at any age, including loss of previously acquired skills.

Milestones are guides — normal development varies. For infants born preterm, use corrected age through approximately 24 months. The AAP recommends standardized developmental screening at 9, 18, and 30 months, and autism-specific screening at 18 and 24 months.

Reference Scharf RJ, Scharf GJ, Stroustrup A. Developmental Milestones. Pediatrics in Review. 2016;37(1):25–37 (Table 3, Developmental Milestones; Table 5, Developmental Red Flags).

Tubes & Lines

Airway · gastric · urinary · chest drainage

🫁

ETT Size & Depth

Tube size · Depth · Suction catheter

▾

Age

years

Tube Type

ETT size (ID) —

Depth at lip —

Oral intubation depth estimate only. Confirm placement with CXR, ETCO₂ and clinical assessment. For neonates <35 weeks, use neonatology-specific guidelines.

Formula


Uncuffed ID = (Age/4) + 4
Cuffed ID   = (Age/4) + 3.5
Depth (cm)  = (Age/2) + 12

Reference APLS / PALS Guidelines. Cole F. Pediatric formulas for the anesthesiologist. AMA J Dis Child. 1957. Use with clinical judgment; smaller tubes may be needed for anatomic variation.

🩺

NG Tube & Urinary Catheter

Sizes by age (French)

▾

Age — years

Months

Reference WHO Pocket Book of Hospital Care for Children, 2nd ed. (Equipment sizes by age/weight). Cross-check rule of thumb: NG/Foley (Fr) ≈ 2 × uncuffed ETT internal diameter (mm). Ranges extend WHO bands (to 7 y) with standard adolescent sizing; individualise to the child.

🩻

Chest Tube

Size by age (French)

▾

Age — years

Months

Reference Fleisher & Ludwig's Textbook of Pediatric Emergency Medicine, 7th ed. Roberts & Hedges' Clinical Procedures in Emergency Medicine & Acute Care, 7th ed.

Drugs

Reference dosing for common drugs · weight-based calculator

💊

Pediatric Drug Doses

Search a drug · weight & age-based dosing · mg only

▾

Search drug

Weight

Enter weight to calculate the dose.

Age — years

+ months

Enter age — this drug is selected by age.

Category

Drug

Generic dose calculator

💊

Generic Dose Calculator

mg/kg weight-based dosing

▾

⚠️ No drug recommendations provided. Enter doses as prescribed. This tool performs calculations only and does not validate clinical appropriateness.

Weight

Dose

mg/kg

Dose type

Frequency

Concentration (optional)

mg/mL

Max single dose (optional)

Max daily dose (optional)

mg/day

Dose per administration —

Total daily dose —

Volume per dose —

Labs

Calcium · Anion gap · FENa · Protein/creatinine · Unit converter

🧪

Corrected Calcium

Albumin-corrected serum calcium (Payne formula)

▾

Total Calcium

mmol/L

Serum Albumin

g/L

Payne RB et al. Interpretation of serum total calcium. Ann Clin Biochem. 1979. Formula: Corrected Ca = Measured Ca + 0.02 × (40 − Albumin g/L). For ionised calcium, request a blood gas.

⚗️

Anion Gap

With optional albumin correction

▾

Sodium (Na⁺)

mmol/L

Chloride (Cl⁻)

mmol/L

Bicarbonate (HCO₃⁻)

mmol/L

Albumin correction

Corrects for hypoalbuminaemia

AG = Na⁺ − (Cl⁻ + HCO₃⁻). Normal 8–12 mmol/L. Albumin correction: AG + 2.5 × (4 − albumin g/dL). Delta ratio = (AG − 10) / (24 − HCO₃⁻). Emmett M, Narins RG. Medicine. 1977.

💧

Fractional Excretion of Sodium

FENa — prerenal vs intrinsic AKI

▾

Urine sodium

mmol/L

Serum sodium

mmol/L

Urine creatinine

Serum creatinine

Tap the unit to switch between mg/dL and µmol/L — both creatinines switch together and cancel out in the formula.

Formula & interpretation FENa (%) = (UNa × SCr) ÷ (SNa × UCr) × 100. <1% suggests prerenal (sodium-avid); >2% suggests intrinsic renal injury/ATN; 1–2% indeterminate. Cautions: unreliable on diuretics (use FEUrea instead) and in CKD, obstruction, or acute glomerular disease. Neonates have higher baseline FENa (immature tubules) — in term neonates <3% may still indicate volume depletion. Source: MDCalc; Steiner RW. Am J Med. 1984.

🧫

Urine Protein : Creatinine Ratio

UPCR — spot urine proteinuria

▾

Urine protein

mg/dL

Urine creatinine

mg/dL

Age — years

Months

Interpretation (mg/mg) Normal: <0.2 (children >2 y) · <0.5 (6–24 months). Abnormal (non-nephrotic): 0.2–2. Nephrotic-range: >2 (≥3 by stricter criteria). 1 mg/mg ≈ 113 mg/mmol. Use a first-morning specimen — later/post-exercise samples overestimate (orthostatic proteinuria). Source: Hogg RJ et al. Pediatrics. 2003; KDIGO.

🔁

Lab Unit Converter

Conventional ↔ SI units

▾

Analyte

Conventional

—

⇌

—

Conversion factors SI value = conventional × factor. Factors per AMA Manual of Style / IFCC SI conversion tables. Common pediatric analytes included; verify against your local laboratory's reported units and reference ranges.

GI & Nutrition

Infant Feeding · IBD Scores (wPCDAI · PUCAI)

🍼

Infant Feeding Estimate

Milk volume · term infants ≤12 months

▾

Not for use in: preterm infants · NICU graduates · congenital heart disease · renal or metabolic disease · tube feeds · faltering growth · acute dehydration · fluid restriction. Use individualised clinician/dietitian plan.

Age

Weight

References
AAP / HealthyChildren.org infant formula feeding guidance. WHO Infant and Young Child Feeding principles. Australian Infant Feeding Guidelines (NHMRC 2012). Royal Children's Hospital Melbourne neonatal fluid and feed guidelines. NICE faltering growth guideline NG75.

🔬

wPCDAI

Weighted Pediatric Crohn's Activity Index · 0–125

▾

Mathematically weighted 8-item version of PCDAI. Based on recall over the previous week. Excludes height velocity, haematocrit, and abdominal examination (statistically redundant in the model).

History (past week)

Abdominal Pain

None0

Mild — brief, does not interfere with activities10

Moderate–severe — daily, longer lasting, affects activities, or nocturnal20

General Well-being

Well — no limitation of activities0

Below par — occasional difficulty with age-appropriate activities10

Very poor — frequent limitation of activity20

Stools per Day

0–1 liquid, no blood0

Up to 2 semi-formed with small blood, or 2–5 liquid7.5

Gross bleeding, ≥6 liquid, or nocturnal diarrhoea15

Examination

Weight

Gain, or voluntarily stable/loss0

Involuntarily stable, or loss 1–9%5

Loss ≥10%10

Peri-rectal Disease

None, or asymptomatic tags0

1–2 indolent fistulae or fissures, scant drainage, no tenderness7.5

Active fistula, drainage, tenderness, or abscess15

Extra-intestinal Manifestations

Fever ≥38.5°C ×3 days/week, definite arthritis, uveitis, erythema nodosum, pyoderma gangrenosum

None0

≥1 finding10

Laboratory

ESR

<20 mm/hr0

20–50 mm/hr7.5

>50 mm/hr15

Albumin

≥3.5 g/dL0

3.1–3.4 g/dL10

≤3.0 g/dL20

out of 125

Interpretation


<12.5     Remission
12.5–<40  Mild activity
40–57.5   Moderate activity
>57.5     Severe activity

Response: ≥17.5-point decrease. Remission: score <12.5.

Reference Turner D, Griffiths AM, Walters TD, et al. Mathematical weighting of the pediatric Crohn's disease activity index (PCDAI) and comparison with its other short versions. Inflamm Bowel Dis. 2012;18(1):55–62. PMID: 21351206

🔬

PUCAI

Ulcerative Colitis Activity Index · 0–85

▾

Non-invasive. No labs or endoscopy required. Validated in children with UC.

Abdominal Pain

No pain0

Pain can be ignored5

Pain cannot be ignored10

Rectal Bleeding

None0

Small amount, in <50% of stools10

Small amount, in ≥50% of stools20

Large amount (>50% of stool content is blood)30

Stool Consistency (most stools)

Formed0

Partially formed5

Completely unformed10

Number of Stools per 24h

0–20

3–55

6–810

>815

Nocturnal Stools (causing waking)

No0

Yes10

Activity Level

No restriction of activity0

Occasional limitation of vigorous activity5

Severe restriction — unable to perform above-average physical exertion10

out of 85

Interpretation


<10      Remission
10–34    Mild activity
35–64    Moderate activity
≥65      Severe activity

Response to therapy defined as ≥20-point decrease. Remission <10. Acute severe UC ≥65.

Reference Turner D, Otley AR, Mack D, et al. Development, validation, and evaluation of a pediatric ulcerative colitis activity index. Gastroenterology. 2007;133(2):423–432.

Cardiology

Blood Pressure · QTc Interval

🫀

Paediatric BP Classifier

Ages 1–17 · AAP 2017

▾

Age

yrs

Sex

Height

Systolic BP

mmHg

Diastolic BP

mmHg

Classification (AAP 2017)


Normal       < 90th percentile
Elevated     90th – <95th percentile
Stage 1 HTN  ≥95th percentile OR ≥130/80
             (whichever is lower)
             AND < 95th+12 mmHg
Stage 2 HTN  ≥95th+12 mmHg OR ≥140/90

Height percentile derived from CDC 2000 LMS growth charts and used to look up the age/sex/height-specific BP threshold from the AAP 2017 normative tables.

Reference Flynn JT, Kaelber DC, Baker-Smith CM, et al. Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents. Pediatrics. 2017;140(3):e20171904.

⚡

Corrected QT Interval (QTc)

Bazett formula · Detects prolonged QT

▾

Heart Rate / Pulse

bpm

Paper Speed

QT Interval

msec

ECG Grid Reference

At 25 mm/sec: 1 large box = 200 msec · 1 small box = 40 msec
At 50 mm/sec: 1 large box = 100 msec · 1 small box = 20 msec

QTc (Bazett) —

RR interval —

Normal QTc: <440 ms (males) · <450 ms (females) · <460 ms (children)

Bazett Formula


RR (sec) = 60 / HR
QTc = QT (sec) / √RR

QTc prolonged if >460 ms in children, >440 ms males, >450 ms females. Borderline: 440–460 ms. Consider drug effects, electrolyte disturbances, channelopathies.

Reference Bazett HC. An analysis of the time-relations of electrocardiograms. Heart. 1920;7:353–370.

Schwartz PJ et al. Diagnostic criteria for the long QT syndrome. Circulation. 1993;88:782–784.