Hi
It depends what you are after.
With A1 containing 17.5% (or containing 0.175)
With B1 containing the Net of VAT value
Vat to charge =B1*A1
Gross figure including VAT =B1*(1+A1)
To convert from Gross figure to Net of VAT figure, if Gross value is in
C1
Net = C1/(1+A1)