Quick guide
How to use this calculator
- Enter a finite decimal.
- Read the least integer greater than or equal to it.
- Notice that negative values move toward positive infinity.
Calculation method
Ceiling points upward
An integer remains unchanged. Any positive fractional remainder advances to the next integer; a negative fractional value discards its fraction toward positive infinity.
Worked example
Ceiling of a negative decimal
−1 is the smallest integer that is still greater than −1.2.
ceil(−1.2) = −1
Supported inputs
Precision and limits
Exact decimal input
Finite decimals use integer-scaled arithmetic, with no binary floating-point conversion.
Input boundary
Unless stated otherwise, use at most 200 digits total and 100 digits after the decimal marker.