What this calculator does
Round to the nearest fraction works out rounds a decimal to the nearest 1/2, 1/4, 1/8, 1/16 or any denominator you choose. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formularounded numerator = round(x × denominator); simplify by dividing by gcd
The inputs explained
| Field | What to enter |
|---|---|
| Decimal value | A number. Starts at 3.34. |
| Round to nearest 1/… | A number. Starts at 16. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with decimal value
Every other input is held at the calculator’s starting values while decimal value varies. Select any row to load that scenario into the calculator.