Math & Numbers
Effect Size Calculator
Calculate Cohen d, Hedges g, Cohen h for proportions, or correlation r effect sizes from summary statistics
json· JSON resultOpen tool
Quick start
Call this tool from your code in three languages.
cURL
curl -X POST 'https://api.elysiatools.com/en/api/tools/effect-size-calculator' \
-H 'Content-Type: application/json' \
-d '{"effectType":"cohen-d","group1Mean":105,"group2Mean":100,"group1Sd":15,"group2Sd":15,"group1Size":30,"group2Size":30,"proportion1":0.6,"proportion2":0.5,"correlation":0.3,"decimalPlaces":4}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
HTTP
POST https://api.elysiatools.com/en/api/tools/effect-size-calculatorParameters
| Name | Type | Required | Description |
|---|---|---|---|
| effectType | select | No | — |
| group1Mean | number | No | — |
| group2Mean | number | No | — |
| group1Sd | number | No | — |
| group2Sd | number | No | — |
| group1Size |
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:
mcp.json
{
"mcpServers": {
"elysiatools-effect-size-calculator": {
"name": "effect-size-calculator",
"description": "Calculate Cohen d, Hedges g, Cohen h for proportions, or correlation r effect sizes from summary statistics",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=effect-size-calculator",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
tools/list
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
tools/call
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "effect-size-calculator",
"arguments": {
"effectType": "cohen-d",
"group1Mean": 105,
"group2Mean": 100,
"group1Sd": 15,
"group2Sd": 15,
"group1Size": 30,
"group2Size": 30,
"proportion1": 0.6,
"proportion2": 0.5,
"correlation": 0.3,
"decimalPlaces": 4
}
}
}Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).
Questions or issues? Contact [email protected]