How it works
Divide the number by the multiple, round the quotient, and multiply back.
round_to_multiple(x, m) = round(x / m) × m
"Up only" uses ceiling (smallest multiple ≥ x) and "down only" uses floor (largest multiple ≤ x).
Common uses: rounding prices to the nearest 5¢ or 5p, rounding ages to the nearest 5 years, rounding minutes to the nearest 15 (quarter hour) for billing, rounding paint quantities up to whole tins.
FAQ
Can the multiple be a decimal like 0.05?
Yes — that's how you round prices to the nearest 5¢. The calculator handles any positive multiple.
What about negative numbers?
"Nearest" rounds to the closer multiple in either direction. "Up" goes toward +∞, "down" toward −∞ — so for negatives, "up" gives a less-negative number.