This is a very basic calculation revolving around percentages. Just take the sale price, multiply it by the commission percentage, and divide it by 100. An example calculation: a blue widget is sold for $70. The salesperson works on a commission — they get 14% out of every transaction, which amounts to $9.80.

So the formula is:

commission amount = sale price × commission percentage / 100.

So now you know how to calculate commission. Now that you have this figure, there's a problem with who will cover this cost — usually, it's the selling party (whoever hired the salesperson to do the job). To calculate their revenue, we need to calculate the percentage decrease:

real revenue = sale price - sale price × commission percentage / 100. In our example, it's
$70 - $70 × 14 / 100 = $70 - $9.80 = $60.20.

It's not very common, but sometimes it's the buyer who pays for the salesperson's remuneration. In those cases, we need the percentage increase formula:

price with commission = base price + base price × commission percentage / 100. In our example, it's $70 + $70 × 14 / 100 = $70 + $9.80 = $79.80.