Why do I care how you calculate your costs?

Different accounting or banking systems will always calculate their values differently, Buildxact is no different in this regard. Whether it is rounding up or down, how many decimal places they round to or allow. This guide will walk you how we handle this on our side.

How many decimal places can I enter inside Buildxact

Buildxact currently allows you to enter up to 2 decimal places for unit cost per item, this applies across the whole system. Quantity allows for 3 decimal places.

A common question is how can I enter an item that I have a cost for that is more than 2 decimal places, eg the cost of a single nail in a box of 100 nails. In this case we suggest rather than trying to enter the single item cost, changing the UOM to 'Box' and setting the price of the item per box.

Estimate Costings - How does the cost, markup and tax calculation work?

Each item will have a few stored values.

  • Unit cost

  • QTY (quantity)

  • Total

  • Markup

  • GST

  • Quote Total

When you enter a unit cost and QTY into Buildxact, a resulting cost will be calculated as a basic QTY X unit cost.

9.9 X $2.36 = $23.364 Total. This however will be rounded to the CLOSEST 2 decimal places which is $23.36

This is stored as the Total for the estimate item.

This will also calculate any markup on the item if a markup % is applied.

Markup is simply the Total calculated previously + the markup %

$23.36 * 15% = $3.504 Markup. This however will be rounded to the CLOSEST 2 decimal places which is $3.5

This will also calculate any tax applicable for this item based on current Tax Profile using the. The tax is calculated off the Total + Markup ($26.86)

$28.86 * 10% = $2.686. This however will be rounded to the CLOSEST 2 decimal places which is $2.69

This is stored per estimate item as the Tax.

The Quote Total of each item gives you an idea of the total that will appear on the Quote. This is simply the Total + Markup + Tax

This gives us an estimate item total of $23.36 + $3.5 + $2.69 = 29.55

Where this may cause confusion is, as your estimate gets larger and if you were to try and work out markup or tax yourself.

If you have a whole estimate with the following values:

Total - $13,804.74

Markup - $0.00

Tax - $1,380.50


Quote Total - $15,185.24

If you were to try and work this out yourself, you would see a different value.

$13,804.74 * 10% = 1,380.474, but we need to round to the CLOSEST 2 decimal - $1,380.47

$13,804.74 + $1,380.47 = $15,185.21. If you were to compare Buildxact's costs and your own:
Buildxact calculation - $15,185.24

Manual calculation - $15,185.21

This gives a discrepancy of 3 cents due to the accumulated rounding values. As your estimate grows in size this difference can increase.

Is Buildxact alone in calculating this way?

Not at all, there are plenty of examples where single costs are rounded then added which can lead to the final tax vs total loooking out of sync. The most notable example is a software we connect with, Xero. The below image is from this Xero help article https://central.xero.com/s/article/How-GST-works-in-Xero#HowXerocalculatesGST

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