The default rule
Monetary outputs are calculated with decimal-safe operations rather than binary floating-point. Unless a formula specification says otherwise, the final currency boundary uses half-up rounding to the nearest cent. Intermediate values remain unrounded so a sequence of steps does not accumulate avoidable rounding error.
| Value | Calculation rule | Display rule |
|---|---|---|
| Currency | Decimal-safe and unrounded between formula steps | Half-up to cents by default |
| Percentages | Stored as validated decimal strings | Enough precision to explain the result |
| Hours and capacity | Preserve the entered precision | Units always shown |
| Presentation price | Does not replace the exact result | Optional cent, nickel, or dollar increment |
A worked example
For a $100 cost and a 40% target gross margin, the unrounded selling price is100 ÷ (1 − 0.40) = 166.666…. The monetary result displays as $166.67. Gross profit displayed from that result is $66.67. The formula trace retains enough precision to explain why the price rounded upward.
Presentation increments
A business profile may select a one-cent, five-cent, or one-dollar presentation increment. That choice can make a suggested price easier to quote, but it never mutates the underlying calculation. Exports distinguish exact calculation values from any rounded presentation value where both are relevant.
Recalculating, exporting, and importing the same scenario must not cause the value to drift by a cent.
Percentage points are not percent change
Sensitivity tables describe nearby margins in percentage points. Moving from a 30% margin to a 35% margin is a five-point increase, not a 5% relative increase. Labels preserve that distinction so a nearby scenario cannot be mistaken for a change in cost.
See the complete formula
The calculation methodology identifies each formula boundary, while every live tool includes the formula version and substituted values in its trace. If a displayed result does not follow this policy, report it.