Plan fluids using weight, dehydration, fever, and losses. Compare daily totals and hourly infusion targets. Use results carefully alongside clinical judgment and local protocols.
The calculator uses a responsive grid: three columns on large screens, two on smaller screens, and one on mobile.
Holliday-Segar daily method: 100 mL/kg for the first 10 kg, 50 mL/kg for the next 10 kg, and 20 mL/kg for each kilogram above 20 kg.
4-2-1 hourly rule: 4 mL/kg/hr for the first 10 kg, 2 mL/kg/hr for the next 10 kg, and 1 mL/kg/hr above 20 kg.
Adult fixed methods: Daily maintenance = weight × 30 or 35 mL/kg/day.
Custom method: Daily maintenance = weight × user-selected mL/kg/day.
Du Bois BSA: BSA = 0.007184 × height(cm)0.725 × weight(kg)0.425
BSA maintenance: Daily maintenance = BSA × 1500 mL/m²/day.
Dehydration deficit: weight × dehydration% × 10
NPO deficit: base maintenance hourly × NPO hours
Fever adjustment: add 10% maintenance for each °C above 37
Adjusted maintenance: base maintenance × fever multiplier × stress factor
Initial hourly rate: adjusted hourly maintenance + losses/hr + deficit replacement/hr - oral intake/hr
24-hour net requirement: adjusted maintenance + ongoing losses + total deficit - oral intake
Enter the patient type, weight, and height if you want the BSA method.
Choose the maintenance method that matches your workflow or protocol.
Add dehydration percentage, NPO hours, and ongoing losses for replacement planning.
Enter oral or enteral intake to offset the estimated intravenous requirement.
Adjust temperature and stress factor when metabolic demand is higher.
Submit the form to view the result, summary cards, graph, and download tools above the calculator.
| Scenario | Weight | Method | Dehydration | NPO | Losses | Temp | Stress | Approx. 24h net |
|---|---|---|---|---|---|---|---|---|
| Pediatric gastroenteritis case | 18 kg | Holliday-Segar | 5% | 6 hr | 300 mL/day | 38.0 °C | 1.05 | 2967 mL |
| Adult perioperative case | 70 kg | 30 mL/kg/day | 2% | 8 hr | 500 mL/day | 37.5 °C | 1.10 | 5026 mL |
| Moderate pediatric dehydration | 25 kg | 4-2-1 rule | 6% | 4 hr | 250 mL/day | 37.8 °C | 1.00 | 3185 mL |
It estimates maintenance fluid needs, dehydration deficit, NPO deficit, ongoing losses, oral intake offset, and hourly rates for a planned replacement window.
No. It is a structured estimate for planning. Final prescribing still needs clinician review, patient reassessment, electrolyte decisions, and local policy alignment.
It is commonly used for pediatric maintenance calculations. Many teams use it for children when a weight-based daily estimate is needed.
Fever can increase insensible losses and metabolic demand. This calculator adds 10% maintenance per degree Celsius above 37 as a simple planning adjustment.
The stress factor lets you scale maintenance needs upward or downward when illness, postoperative stress, or lower demand changes the expected baseline requirement.
No. It estimates fluid volume only. Sodium, potassium, dextrose, acid-base status, and fluid type still need separate clinical selection.
Use extra caution. Severe dehydration, shock, sepsis, burns, kidney injury, or cardiac disease often need more detailed assessment than a simple maintenance calculator provides.
The initial rate includes deficit replacement during the chosen time window. The continuing rate shows the estimated hourly requirement once that replacement period ends.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.