Quick guide
How to use this calculator
- Enter a finite decimal.
- Choose the large place value.
- Read the half-up result; an exact tie moves away from zero.
Calculation method
Compare with half the chosen increment
The value is divided by the selected power of ten. A discarded magnitude below half stays; half or more moves to the next magnitude.
Worked example
An exact thousand tie
12,500 lies halfway between 12,000 and 13,000, so half-up chooses 13,000.
12,500 → 13,000
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.