Dehydration in Children Calculator

The Clinical Dehydration Scale (Freedman) scores four domains—general appearance, eyes, mucous membranes, and tears—each from 0 to 2 for a total 0–8. We map 0 to no dehydration, 1–4 to some dehydration, and 5–8 to moderate–severe dehydration. WHO oral rehydration therapy (ORT) volumes are suggested from the category, and IV boluses are flagged for hypovolemia/shock.

• Some dehydration: ORS 75 mL/kg over 4 hours (typical WHO Plan B; range 50–100 mL/kg based on severity).
• Moderate–severe: ORS 75–100 mL/kg over 4 hours and consider IV bolus 20 mL/kg if unstable.

1. Set a target volume from severity category and child weight.
2. Start with small frequent volumes (for example 5-10 mL every 5 minutes), then increase as tolerated.
3. If emesis occurs, pause briefly and restart with smaller volumes rather than stopping entirely.
4. Track intake, emesis, stool losses, and urine output in real time to guide next reassessment.
5. Escalate to IV fluids when oral strategy fails, perfusion worsens, or red flags emerge.

Clinical dehydration assessment in children relies on a combination of exam findings, vital signs, weight change, and history rather than a single sign or tool. The Clinical Dehydration Scale was developed to provide a structured way to summarize several key findings into a 0–8 score that correlates with fluid deficit and the need for more intensive rehydration strategies.

Even so, performance varies by setting and examiner, and children with underlying cardiac, renal, or metabolic disease may not fit typical patterns. Laboratory markers such as serum electrolytes, bicarbonate, and blood urea nitrogen can refine the picture in moderate–severe cases or when the diagnosis is uncertain. Use the score and ORS volumes generated here as a starting framework, then individualize based on serial exams and response to therapy.

Parents and caregivers should receive clear instructions about when to return or seek urgent care (e.g., persistent vomiting, worsening lethargy, inability to maintain oral intake, or new red‑flag symptoms). Document the scale findings, planned ORT or IV strategy, and safety‑net advice so that future clinicians can see how decisions were made.

• CDS 0 (no dehydration): focus on maintenance intake, return precautions, and monitoring for new red flags.
• CDS 1–4 (some dehydration): treat with WHO Plan B–style ORT using the suggested volume and reassess every 1–2 hours.
• CDS 5–8 (moderate–severe): treat as higher risk—expedite evaluation, consider IV bolus for hypovolemia, and plan ongoing loss replacement after initial resuscitation.
• Always individualize for age, comorbidities, and local protocols; CDS complements, rather than replaces, clinical assessment.

• Signs of shock (weak pulses, hypotension, AMS) → immediate isotonic IV bolus 20 mL/kg and urgent evaluation.
• Intractable vomiting, bilious emesis, severe abdominal pain, bloody stools, or suspected surgical abdomen → ED evaluation.
• High-risk infants and children with comorbidities—use lower threshold to escalate care.
• Persistent tachycardia, worsening capillary refill, or declining urine output despite therapy should trigger urgent reassessment.

• Persistent perfusion deficits or altered mental status despite rehydration attempts.
• Inability to maintain ORS due to ongoing emesis or deteriorating intake tolerance.
• Concerning abdominal findings suggesting surgical or alternate high-risk etiology.
• Worsening vitals or urine output trend inconsistent with expected response.

• Record CDS component findings, not just total score.
• Document ORS/IV plan with exact volume targets and reassessment interval.
• Include red-flag return precautions in caregiver language.
• At transition of care, hand off trajectory: perfusion trend, urine output, emesis frequency, and response to interventions.

• CDS component findings and total score with timestamp.
• ORS or IV plan with exact volume targets and response so far.
• Current perfusion, urine output, emesis/stool trajectory.
• Red-flag status and escalation actions taken/pending.
• Next reassessment interval and trigger for urgent escalation.

• IV Maintenance Fluids
• Glucose Infusion Rate (GIR)
• Fluids, renal and physiology calculators hub

• Freedman SB, et al. Clinical Dehydration Scale in children. CMAJ. 2010.
• WHO guidance on diarrhoea and oral rehydration therapy
• CDC oral rehydration and acute gastroenteritis guidance