Trying to figure out total values for percentages?

I'm trying to calculate total fundraising needed to win incentive prizes.


Basically, if the incentive prize costs us $15, that needs to be 5% of the total amount raised. How would I go about finding what the total amount raised needs to be?


If you could provide a formula, that would be great because I'll need to figure out the number for multiple prizes.





Thanks in advance!Trying to figure out total values for percentages?
$15 = 5% you want to know what would be 100%





to calculate 1% 15/5 = 3


so 100% = 3 x 100 = $300





formula





incentive cost x 100 / incentive percentage