Round Numbers Down
Apply mathematical floor to every line: the result is the greatest unit multiple less than or equal to the input.
A QUICK WALKTHROUGH
How to use this tool
- Enter one number per line.
- Choose decimal places or enter a positive rounding unit.
- Round all lines downward and copy the results.
Mathematical definition
For a positive unit u, round down as floor(x / u) × u. This is directed downward on the number line, so negative values move away from zero when they are not already on a unit multiple.
Input validation
Each non-empty line must be a finite decimal number. Decimal places must be an integer from 0 to 15; a unit must be finite and greater than zero.
Private local processing
All calculations run in your browser. Input is not uploaded or stored.
GOOD TO KNOW
Common questions
Is this ordinary half-down rounding?
No. It always uses mathematical floor, regardless of the following digit.
How are negative values handled?
They round downward on the number line: floor(-2.01) is -2.1 at one decimal place.
Can I use a custom increment?
Yes. Select Unit multiple and enter any positive finite value.