REMOVE TAX FROM AN INCLUSIVE TOTAL
Remove GST from an Amount
Separate the original price and GST from a tax-inclusive amount. Enter the full amount, select its rate and choose Remove GST in the calculator.
Why the divisor matters
GST is part of the total, so the inclusive price represents 100% plus the tax rate. At 18%, divide the total by 1.18. This gives the correct taxable value and avoids the error of subtracting 18% from the total.