Number.RoundDown
NumberRounds a number down toward zero (floor).
Syntax
Number.RoundDown(number as nullable number, optional digits as nullable number) as nullable numberParameters
| Name | Type | Required | Description |
|---|---|---|---|
number | number | Yes | The number to round down. |
digits | number | No | Number of decimal places (default 0). |
Return Value
number — The number rounded down to the specified precision.
Remarks
Number.RoundDown always rounds toward zero, truncating any fractional part beyond the specified number of digits. When digits is omitted it defaults to 0, producing an integer. This behaves like a floor function for positive numbers.
Use this when you need to assign items to discrete buckets — for example, grouping prices into $10 bands by rounding down to the nearest ten.
Examples
Example 1: Floor product prices to nearest ten
Table.AddColumn(
Table.SelectColumns(Products, {"ProductName", "Price"}),
"PriceTier", each Number.RoundDown([Price], -1), type number
)Result
ProductName | Price | PriceTier | |
|---|---|---|---|
| 1 | Widget A | 25 | 20 |
| 2 | Gadget B | 50 | 50 |
| 3 | Widget C | 15 | 10 |
| 4 | Gadget D | 75 | 70 |
| 5 | Thingamajig E | 120 | 120 |
Compatibility
✓ Power BI Desktop✓ Power BI Service✓ Excel Desktop✓ Excel Online✓ Dataflows✓ Fabric Notebooks