# Calculate loss and profit from percentage

The current BTC price is 2700\$.
The price has increased by +34% in 7Days.
I hold 3.011 BTC, how can i calculate my profit?

```currentPrice = 2700;
percent = 34;
holdings = 3.011;
alert(  calcPec(currentPrice,percent,holdings)  );
```

The current BTC price is 2700\$.
The price has increased by -7% in 2Days.
I hold 3.011 BTC, how can i calculate my loss?

```currentPrice = 2700;
percent = -7;
holdings = 3.011;
alert(  calcPec(currentPrice,percent,holdings)  );
```

```// This is what i have but it is not correct
function calcPec(currentPrice,percent,holdings)
{
res = currentPrice*percent/2;
sum = holdings*res;
return '\$'+sum;
}
```

## Answer

You forgot to divide the percentage by 100 to get a fraction.

```// The current BTC price is 2700\$.
// The price has increased by +34% in 7Days.
// I hold 3.011 BTC, how can i calculate my profit?

currentPrice = 2700;
percent = 34;
holdings = 3.011;
console.log(calcPec(currentPrice, percent, holdings));

// The current BTC price is 2700\$.
// The price has increased by -7% in 2Days.
// I hold 3.011 BTC, how can i calculate my loss?

currentPrice = 2700;
percent = -7;
holdings = 3.011;
console.log(calcPec(currentPrice, percent, holdings));

function calcPec(currentPrice, percent, holdings) {
const curr = holdings * currentPrice;
const changed = curr * (1 + (percent / 100));
return '\$' + (changed - curr);
}

```

In future you probably want to define your percentage as a fraction to begin with, to avoid errors like this. So instead of `percent = 34` you’d do `percent = 0.34`

EDIT fixed other errors too;