Several years ago I wrote an article on how to charge just the right amount to cover the fees Square charges merchants. Today I wanted to donate to a controversial GoFundMe campaign an old friend of mine posted. I thought about donating exactly the right amount to afford him a 1 month bus pass, but I knew that to do that I'd have to account for whatever fees GoFundMe charges. I got this.

GoFundMe charges a flat 7.9% fee + 30¢ per donation as of this post, so let's say you want to give someone $100 but you want to cover the fees for them. How do you arrive at the correct donation?

You could add 7.9% + 30¢ to arrive at $108.20... um $109 (they only do whole dollar amounts), but when GoFundMe takes their cut your donee gets $100.09. That's super boring. Rounding to the nearest dollar really simplifies things! So let's pretend they take pennies so we can do some math.

We're looking for the value *x* such that `x-x*7.9%-0.30=y`

where *y* is the
amount you want to end up with. Simplify that using algebra and you get
`x=(y+0.30)/(1-7.9%)`

or rather `x=(y+0.30)/92.1%`

. For you folks without a %
on your calculator that's `x=(y+0.30)/0.921`

.

It's easy enough to see how to generalize the solution, so instead here's a form to help you calculate the right amount.

$42

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