Rounding Calculator
Round numbers to any place value or significant figures.
Rounded
3.14
Rounded up (ceiling)
3.15
Rounded down (floor)
3.14
Rounding error
0.00159
The half-up convention
Standard rounding sends digits 5–9 up and 0–4 down: 3.145 → 3.15 at two places. Financial systems sometimes use banker's rounding (half to even) so that up- and down-rounds cancel over many transactions.
Round late
Rounding intermediate results compounds error — 3.14 × 3.14 differs from π² by more than the final rounding would. Keep full precision through the calculation and round once at the end, to the precision your context justifies.
Frequently asked questions
- How does the Rounding Calculator work?
- Round numbers to any place value or significant figures.
- Is the Rounding Calculator free to use?
- Yes. The Rounding Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
Related calculators
Percentage Calculator
Solve any percentage problem: percent of, percent change, and more.
Fraction Calculator
Add, subtract, multiply, and divide fractions with simplified results.
Scientific Calculator
A full scientific calculator with trig, logs, and exponents.
Random Number Generator
Generate random numbers in any range, with or without repeats.