Multiply the entered quantity by the unit price, then round the resulting money amount to cents using the creator’s half-up rule. Keep the quantity at its supported precision until that multiplication. Rounding the quantity first can change the charge even when the final money amount must have only two decimal places.
This is the first numerical step in the invoice calculation workflow. The current creator accepts positive quantities with up to four decimal places and nonnegative unit prices with up to two. It then applies supported percentage discounts and tax in later steps, so the initial product is not necessarily the final line contribution.
Separate input precision from output precision
A quantity of 1.375 and a unit price of 20.00 produce 27.50000 before monetary formatting. The displayed money amount is 27.50. The extra quantity digits were useful even though the resulting amount has two decimals. Reducing the quantity to 1.38 first would produce 27.60 instead.
Preserve the source measurement or approved duration in the quantity field within the four-decimal limit. Do not reduce every quantity to two decimals merely because prices use two. These fields describe different kinds of value and have different supported precision.
The unit must remain consistent with the rate. A precise number of metres cannot be multiplied by a rate per centimetre without an appropriate conversion. The creator’s unit text does not perform that conversion or verify whether the quantity represents the supplied goods or services.
Apply the stated rounding rule
Half-up rounding sends an exact half-cent upward for the positive values supported here. A quantity of 0.125 at a price of 10.00 gives an initial product of 1.25, with no rounding change. A quantity of 0.125 at 1.00 gives 0.125, which becomes 0.13 as a money amount.
Compare that with 0.1249 at 1.00, which becomes 0.12. These small examples make the boundary visible. Use them to understand the policy, not to alter quantities until the invoice produces a preferred amount. The entered measurement must still reflect the transaction.
The app implements its supported calculation with fixed-point values. When checking the result independently, use decimal arithmetic or a method that respects the same rounding sequence. A calculator displaying many digits without explaining its rounding policy may not be a reliable comparison at the cent boundary.
Check the later steps separately
After the initial amount is rounded, the creator calculates the percentage discount from that rounded value and rounds the discount to cents. It subtracts that amount to obtain the net line value. Tax is then calculated from the discounted net and rounded separately.
Do not compare a single unrounded expression with the final result and assume a difference means multiplication failed. Retaining all fractions through discount and tax is a different calculation sequence. Review the intermediate stages to identify where the results diverge.
For example, a small quantity can produce a half-cent initial amount, and a later percentage can produce another fractional cent. Each stage can affect the final result. The guide to per-line rounding explains how those decisions accumulate across several rows.
Handle unsupported source precision
A source quantity with five or more decimal places cannot be entered unchanged into the current model. Likewise, a price needing more than two decimals exceeds the current price precision. Do not hide the extra digits in a description and assume the calculation still uses them.
Check whether an agreed alternative quantity and unit basis can represent the charge faithfully. Any such change must preserve the commercial meaning and required precision. If the model cannot do that, use an invoicing system that supports the source basis rather than silently truncating the value.
Avoid changing quantity solely to compensate for a rounded price. That can make the invoice disagree with the measurement evidence. A numerically matching result does not justify representing a different supplied quantity without a sound basis.
Review the result before exporting
Create a short check record showing the exact supported quantity, unit price, initial product and rounded initial amount. Then add the discount and tax steps if applicable. This makes it possible to distinguish an input mismatch from a rounding-policy mismatch later.
You can test the numbers in the creator with fictional data before entering a long real invoice. Change one input at a time and inspect the preview. A representative small test can reveal precision limits before you prepare dozens of rows.
Finally, compare any exported values with the final workspace state. Download a fresh file after edits; an earlier JSON or CSV does not update automatically. The current exports use the application’s model and do not establish that another system uses the same calculation rules or that a formal invoice profile has been satisfied. Check that destination separately before delivery.
When reviewing a spreadsheet comparison, inspect the underlying cell values rather than only the displayed two-decimal format. A cell displaying 0.13 might still contain 0.125 and feed that longer value into later formulas. Explicitly rounding the relevant stage is different from merely formatting its appearance. Record which operation your comparison uses.