[AccessD] A2003:Calculating Percentages - and their currency values

Just straight forward algebra to work it out.
Total = Price + Price * GstRate
So
Divde both sides by Price
Total / Price = 1 + GstRate
Then transpose
Total / (1 + GstRate) = Price
So assuming 12.5 % GstRate
Price = Total / ( 1 + 12.5/100)

This can get a little more confusing in Canada where there is Provincial 
and Federal Sales Tax
and some items have either  no provincial or no Federal Tax.

Darren DICK wrote:

>Hello all
>In Australia we have a sales tax apply to all purchases. It's called GST
>(Like VAT in Britain)
>
>At the moment the Govt. has set this Tax at 10 percent. Makes the maths very
>simple by 
>Just adding 10 percent to each currency amount.
>
>To calculate any TAX inclusive amounts we just divide the grand total by
>1/11 (one eleventh)
>
>So far so good.
>
>Until the Govt. changes the GST Rate (they said they won't but we all know
>they eventually will)
>
>So I don't want to hard code "Divide Grand total by one eleventh" to get any
>GST inclusive amounts.
>If the GST amount is changes to say... 12.5 per cent - it won't work -
>obviously
>
>So.for all the mathematically inclined folk out there..
>Is there a clever formula for working out GST Inclusive prices regardless of
>the Current TAX rate?
>Just like the one eleventh business works for 10 percent?
>
>Many thanks
>
>Darren
>  
>

-- 
Marty Connelly
Victoria, B.C.
Canada