---
title: "symbolSize(for:)"
framework: charts
role: symbol
role_heading: Instance Method
path: "charts/chartproxy/symbolsize(for:)"
---

# symbolSize(for:)

Returns the symbol size for the given data value. Returns nil if the symbol size scale is unavailable, or the value is invalid.

## Declaration

```swift
func symbolSize<P>(for value: P) -> CGFloat? where P : Plottable
```

## Parameters

- `value`: The data value.

## Return Value

Return Value The symbol size corresponding to the data value, or nil if the data value is incompatible with the chart.