# Sandbox.SandboxSystemExtensions.ToDoubleEval

```csharp
static double ToDoubleEval(string expression, double Default = 0)
```

Convert to `T:System.Double`. Might be a string formula. This is always going to be slower than a call to [Sandbox.SandboxSystemExtensions.ToDouble](/api/Sandbox.SandboxSystemExtensions/ToDouble).

### Parameters

- `expression` (`string`)
- `Default` (`double`), default `0`

### Returns

`double`

Declared in [Sandbox.SandboxSystemExtensions](/api/Sandbox.SandboxSystemExtensions).
Assembly: `Sandbox.System`.