How do I formulate total before Gst?

[Maggie1959]

how do I formulate cells to get a total BEFORE gst was added? Example : item
cost 20.00 Gst 1.00 = 21.00 I have a columm for the "item cost" without gst
added...then a gst columm...is there a way to formulate the 'item cost "
cell so I don't have to subtract the gst total from the grand total every
time I enter a price? (Office 2007)

 

[Joe User]

how do I formulate cells to get a total BEFORE gst was added? Example :
item
cost 20.00 Gst 1.00 = 21.00 I have a columm for the "item cost" without
gst
added...then a gst columm...is there a way to formulate the 'item cost "
cell so I don't have to subtract the gst total from the grand total every
time I enter a price? (Office 2007)

 

[Joe User]

how do I formulate cells to get a total BEFORE gst was added?

Ostensibly, if the GST is in B1 (5% or 0.05) and the total after adding GST
is in C1 (21.00), the item cost is:

=ROUND(C1 / (1+B1), 2)

One caveat: the item cost plus GST must be rounded to the smallest coin of
the realm, since it is an actual amount to be paid. (For the same reason, I
rounded the item cost above.) So theoretically, dividing that amount by
1+GST might not result in exactly the original item cost.

But I have not yet come up with an example, based on reasonable GST and item
cost amounts. So maybe it won't be a problem, after all.


[Sorry for the previous empty response. Push the wrong key, I guess.]


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