# EXP function
<a name="EXP"></a>

The EXP function implements the exponential function for a numeric expression, or the base of the natural logarithm, `e`, raised to the power of expression. The EXP function is the inverse of [LN function](LN.md). 

## Syntax
<a name="EXP-synopsis"></a>

```
EXP (expression)
```

## Argument
<a name="EXP-argument"></a>

 *expression*   
The expression must be an INTEGER, DECIMAL, or DOUBLE PRECISION data type. 

## Return type
<a name="EXP-return-type"></a>

EXP returns a DOUBLE PRECISION number. 

## Example
<a name="EXP-example"></a>

Use the EXP function to forecast ticket sales based on a continuous growth pattern. In this example, the subquery returns the number of tickets sold in 2008. That result is multiplied by the result of the EXP function, which specifies a continuous growth rate of 7% over 10 years. 

```
select (select sum(qtysold) from sales, date
where sales.dateid=date.dateid
and year=2008) * exp((7::float/100)*10) qty2018;

qty2018
------------------
695447.483772222
(1 row)
```