Health
Maintenance Fluid Rate (4-2-1 Rule)
Calculate the hourly maintenance fluid rate using the Holliday-Segar 4-2-1 rule: first 10 kg at 4 mL/kg/h, next 10 kg at 2 mL/kg/h, each kg above 20 at 1 mL/kg/h. Also shows the 24-hour total and the 100/50/20 mL/kg/day daily method for cross-checking. Weight in kg or lb (auto-converted). Derived from Holliday-Segar Pediatrics 1957, MDCalc, and Meyers 2009. Not medical advice.
Quick start
Call this tool from your code in three languages.
curl -X POST 'https://api.elysiatools.com/en/api/tools/fluid-maintenance-rate' \
-H 'Content-Type: application/json' \
-d '{"weight":70,"weightUnit":"kg","decimalPlaces":1}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
POST https://api.elysiatools.com/en/api/tools/fluid-maintenance-rateParameters
| Name | Type | Required | Description |
|---|---|---|---|
| weight | number | Yes | Patient body weight, in the unit selected below. |
| weightUnit | select | Yes | — |
| decimalPlaces | number | No | — |
Response format
JSON result
{
"key": {...},
"metadata": {
"key": "value"
},
"error": "Error message (optional)",
"message": "Notification message (optional)"
}MCP integration
Add this tool to your Model Context Protocol server so AI agents can list and call it.
Server configuration
Add this block to your MCP client configuration:
{
"mcpServers": {
"elysiatools-fluid-maintenance-rate": {
"name": "fluid-maintenance-rate",
"description": "Calculate the hourly maintenance fluid rate using the Holliday-Segar 4-2-1 rule: first 10 kg at 4 mL/kg/h, next 10 kg at 2 mL/kg/h, each kg above 20 at 1 mL/kg/h. Also shows the 24-hour total and the 100/50/20 mL/kg/day daily method for cross-checking. Weight in kg or lb (auto-converted). Derived from Holliday-Segar Pediatrics 1957, MDCalc, and Meyers 2009. Not medical advice.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=fluid-maintenance-rate",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "fluid-maintenance-rate",
"arguments": {
"weight": 70,
"weightUnit": "kg",
"decimalPlaces": 1
}
}
}