---
type: "fhirpath-function"
title: "FHIRPath Function: sum"
function: "sum"
category: "Aggregates"
section: "7.2"
source: "fhirpath/functions.json"
---
# FHIRPath Function: sum
_No canonical section match found in index.md._
## Summary
- **Category**: Aggregates
- **Section**: `7.2`
- **Return Type**: `Integer | Long | Decimal | Quantity`
- **Empty Input Result**: `empty`
- **Errors on Multiple Input**: `false`
## Description
Returns the sum of all elements in the input collection (in the same type).
## Arguments
- none
## Type Mapping
- n/a
## Example
```fhirpath
(1.0 | 2.0 | 3.0).sum() // 6.0
```