Equation Help

[WarrenW]

Hi,

My mind must be very tired today because I did this once but can't remember how I did it. I'm trying to take a price such as $100 and then back out the tax (say 6%) so the subtotal price plus the tax equals $100.

In VB6 I want to write a function that I pass the total price of $100 and it returns the new price and the tax amount that totals $100.

So as an equation, I write it as:

$100 = Price + (Price * .06)

If you just calculate the tax on $100 and subtract it, thats too much tax because the new price is lower that $100.

Any thoughts?

Thanks!!!

[riis]

It's very simple:

Price with tax = $100, tax = 6%.

Price + 0.06 * Price = $100
1.06 * Price = $100
Price = $100 / 1.06 = $94.34 (approx)

Generally: PriceWithoutTax = PriceWithTax / (1 + tax)


Since $100 > $94.34, then if you take 6% from each, the 6% from $100 is also greater than the 6% from $94.34, so that's why you end with a value too low.
I bet you ended up with $99.64 instead of $100.