Jomablue automatically calculates tax on Products and Items where applicable - that means prices entered into Jomablue must be a excluding tax.

These amounts also need to be rounded to 4 decimal places.

Why 4? Isn't it normally 2 decimal places?
Although rounding to 4 is less common, it allows Jomablue to more accurately round Tax calculations for totalling. Rounding errors (in the fraction of cents) are common in financial systems and this is no different for Jomablue. Increasing the decimal places to 4 reduces the likelihood of large rounding errors when adding multiple items to a cart and applying multiple levels of discounts to each item.

## Calculating the ex. Tax pricing using Excel or Google Sheets

If you are trying to remove 10% Tax (in the case of Australian GST), we represent that as a decimal of 1.1 (110% of the whole number). If it was 20% tax it would be 1.2 and so on.

Now you can then simply divide the whole number by 1.1.
Below you can see the Tax inclusive value is \$425.00 in cell A3 and the formula used to remove tax which is =A3/1.1 In this case the answer is \$386.36 excluding tax. But wait. We need it to 4 decimal places. This is easily done with the "Increase Decimal" and "Decrease Decimal" buttons in Excel and Google Sheets. Which leaves us with an answer of \$386.3636 excluding tax. 