Math Calculator
Rounding Calculator.
Round any number to decimal places, significant figures, or the nearest step — instantly and clearly.
Rounded Result
3.14
Rounded to 2 decimal places
Original3.1415926535
Modedecimals
Difference-0.0015926535
What Is a Rounding Calculator?
A rounding calculator trims a number to the precision you need — decimal places for money and measurements, significant figures for science, or nearest steps for estimates and inventory.
How Rounding Works
nearest step → round(n ÷ step) × step
For decimal places we use half-up rounding. Significant figures keep the leading meaningful digits and adjust the remaining places accordingly.
Frequently Asked Questions (FAQs)
How do you round to a certain number of decimal places?
Look at the next digit: 5+ rounds up. Example: 3.14159 → 3.14 (2 decimal places).
What are significant figures?
Meaningful digits starting from the first non-zero digit. Rounding 12345 to 3 sig figs gives 12300.
How do you round to the nearest 10 or 100?
Divide by the step, round, multiply back. Example: 847 → nearest 100 = 800.