Rounding Calculator

Number

Supports scientific notation (e.g., 1.23e-4).

Rounding strategy

Choose how .5 is handled (HALF_EVEN = banker’s rounding).

Decimal places Places

Rounds using round(n, places).

Significant figures Figures

Rounds to total meaningful digits (e.g., 0.004567 → 2 s.f. = 0.0046).

Nearest multiple Multiple

Rounds to nearest multiple (useful for prices like 0.05 or increments like 25).

Rounding – Quick Cheat Sheet

Decimal places (dp): keep a fixed number of digits after the decimal point.
Significant figures (s.f.): keep a total count of meaningful digits from the first non-zero.
Nearest multiple: round to the closest step size (e.g., price ticks like 0.05).
Strategies:
- HALF_UP: 1.5 → 2, -1.5 → -2
- HALF_DOWN: 1.5 → 1, -1.5 → -1
- HALF_EVEN (banker’s): ties go to even (2.5 → 2, 3.5 → 4)
- HALF_ODD: ties go to odd (2.5 → 3, 3.5 → 3)
Tip: For extremely large/small numbers, scientific notation is accepted (e.g., 6.02e23).