Health
Serum Osmolality Calculator (Calculated)
Calculate serum osmolality from routinely measured solutes. Conventional formula Osm = 2 × Na + Glucose/18 + BUN/2.8 (Na in mmol/L, glucose & BUN in mg/dL), or the SI-unit form Osm = 2 × Na + Glucose + Urea (all mmol/L). An optional ethanol term (EtOH/4.6) is available when a toxic-alcohol ingestion is being considered. Normal range ≈ 275–295 mOsm/kg. Values < 275 suggest hypo-osmolality (SIADH, primary polydipsia, adrenal insufficiency, hypothyroidism); values > 295 suggest hyperosmolality (hyperglycemia/HHS, hypernatremia, uremia, mannitol, toxic alcohols — the latter also raise the osmolar gap, so measure osmolality and compute the gap). Derived from Dorwart 1975, Rasouli 2014, and MDCalc. Not medical advice.
Quick start
Call this tool from your code in three languages.
curl -X POST 'https://api.elysiatools.com/en/api/tools/serum-osmolality-calculator' \
-H 'Content-Type: application/json' \
-d '{"unitSystem":"conventional","sodium":140,"glucose":110,"bunOrUrea":14,"ethanol":0,"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/serum-osmolality-calculatorParameters
| Name | Type | Required | Description |
|---|---|---|---|
| unitSystem | select | Yes | — |
| sodium | number | Yes | Serum sodium (mmol/L), always in mmol/L regardless of unit system. Physiologic range ~120–160. |
| glucose | number | Yes | Serum glucose. mg/dL under Conventional units, mmol/L under SI units. |
| bunOrUrea | number | Yes | BUN in mg/dL under Conventional units, or serum urea in mmol/L under SI units. |
| ethanol | number | No |
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-serum-osmolality-calculator": {
"name": "serum-osmolality-calculator",
"description": "Calculate serum osmolality from routinely measured solutes. Conventional formula Osm = 2 × Na + Glucose/18 + BUN/2.8 (Na in mmol/L, glucose & BUN in mg/dL), or the SI-unit form Osm = 2 × Na + Glucose + Urea (all mmol/L). An optional ethanol term (EtOH/4.6) is available when a toxic-alcohol ingestion is being considered. Normal range ≈ 275–295 mOsm/kg. Values < 275 suggest hypo-osmolality (SIADH, primary polydipsia, adrenal insufficiency, hypothyroidism); values > 295 suggest hyperosmolality (hyperglycemia/HHS, hypernatremia, uremia, mannitol, toxic alcohols — the latter also raise the osmolar gap, so measure osmolality and compute the gap). Derived from Dorwart 1975, Rasouli 2014, and MDCalc. Not medical advice.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=serum-osmolality-calculator",
"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": "serum-osmolality-calculator",
"arguments": {
"unitSystem": "conventional",
"sodium": 140,
"glucose": 110,
"bunOrUrea": 14,
"ethanol": 0,
"decimalPlaces": 1
}
}
}