Struggling to create a % percentage of a calculation

Hi There

Struggling to create a percentage of a calculation.

I would like to create a formula to get one and a half times a price.

or 150% of the exterior clean calculation and show that added in the quote total with exterior clean.

also how do i show £ in resulting calculations

You should just add "*1.5" in your formula. This will add 150% to your calculation. You should do the same for other percentages. For example "80%" would be "*0.8", "120%" would be "*1.2".