I have a table like this: used to determine commision

Percent
$0 $200,000 1.00%
$200,001 $500,000 2.50%
$500,001 $800,000 4.00%
$800,001 $99,999,999 6.00%

Is there a function to calculate commision using this table?
For example, if the total sales is $600,000, I need to sum 1% of the first
$200,000 and 2.5% of the next $300,000 and 4% of the remaining $100,000.

Thanks, A