Setting a minimum value for a cell.

Hi guys,

I would like to set a formula in a particular cell so that everytime a value in that cell is less than 1 (<1) it gets replaced to 1 automatically.

For example, in case of below my Payable tax amount comes to 0.7. However, minimum amount I have to pay is 1. Is there any formula which I can apply here so whenever my calculation for payable amount comes under 1 it gets automatically replaced to 1?

Cheers!