Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Exact decimal-string rounding avoids binary floating-point tie errors. Up to 80 digits and 20 fractional places; output has exactly the requested number of places.
Example Calculation
- Number: 1.005
- Decimal places: 2
1.005 rounds to 1.01 at two decimal places; −1.005 rounds to −1.01.
Frequently asked questions
How do I use this calculator?
Enter number, decimal places. The result updates automatically. Use Reset to restore the example values.
What method does it use?
Round to the nearest decimal quantum; an exact halfway value rounds away from zero.. Exact decimal-string rounding avoids binary floating-point tie errors. Up to 80 digits and 20 fractional places; output has exactly the requested number of places.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.