Sig Fig Rounding Calculator

Created By : Prasanna
Reviewed By : Phani Ponnapalli
Last Updated at : May 6,2023

Utilize our online Sig Fig Rounding Calculator and easily rounds a given number to the quantity of significant digits that you define in the input box. Just give your input rounding number and significant figures in the relevant input fields and click on the calculate button to avail the output in microseconds with steps.

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Sig Fig Rounding Calculator: Need more assistance to calculate the problems on significant figures rounding? Make a visit to this article i.e., Sig Fig Rounding Calculator and find the information related to rounding significant figures completely. Here, you will get to know what sig fig is and how to round numbers to specified significant figures with examples. Also, read the sig fig rules followed when rounding the given numbers from the further modules.

What is Meant by Sig Fig Rounding & Its Rules?

The process of rounding a given number with the specified significant figures is called sig fig rounding. It applies all the rules to round to significant figures. For example, 1670 rounded to 2 significant digits is 1700.

Rules to Calculate Significant Figures(Sig Fig)

  • Every non - zero digits are significant numbers. For example, 2.43 includes three significant figures
  • The zeroes are significant if the zeros are between numbers, whose actual value is not zero. For instance, 34200057 includes eight significant figures.
  • The zeroes are significant that is after the last non-zero number when the number has a decimal point. For example, 4.050 includes four significant figures.
  • The zero is not a significant number if it is to the left of the first non-zero digit. For instance, 0.002222 includes four significant figures.
  • Trailing zeros are not significant if the number does not have a decimal point. For instance, 500 or 5 × 10^2 only holds one significant figure.
  • In exact numbers, the total number of significant digits is unlimited. Also, same case for defined numbers. 1 meter = 1.0 meters = 1.000 meters = 1.00000000 meters etc.

How to Round Off To Significant Figures Using Rules?

The below given points are some of the rules that should be followed when rounding to sig figs. They are as follows:

  • When the standard rules of rounding numbers apply on a rounding sig figs, except the non-significant digits to the left of the decimal are replaced with zeros.
  • The specified pounding number can't be a negative number and must be higher than 0.
  • A number with 0 significant digits would be 0. Hence, the number to round to must be a positive.
  • Moreover, the specified rounding number must be a number that is either equal to or less than the amount of significant digits present in the number.

Take a look at some solved examples which we have workd out by applying the rounding sig fig rules. Understand the concept by practicing with these problems and verify your answers from offered online sig fig rounding calculator.

Rounding to Significant Figures Calculator Examples


Rounding the Number 205.3359 to sig fig & decimal places


Rounded to How Many SF & DP? Rounded to Significant Figures (SF) Rounded to Decimal Places (DP)
1 200 205.3
2 210 205.34
3 205 205.336
4 205.3 205.3359
5 205.34 205.33590
6 205.336 205.335900
7 205.3359 205.3359000

FAQs on Free Online Sig Figs Rounding Off Calculator

1.How do you do sig figs when rounding?

For rounding to significant figures, we have to follow these steps:

  • First, Look at the first non-zero digit if rounding to one significant figure
  • Next, consider the digit after the first non-zero digit if rounding to two significant figures
  • Draw a vertical line after the place value digit that is needed
  • Look at the next digit, if it is greater than or equal to 5, Add 1 to the previous digit.
  • If it's 4 or less, keep the previous digit as it is.
  • Fill any spaces to the right of the line with zeros, ending at the decimal point if there is one.

2. Do you round down in sig figs?

Yes, we do round down in sig figs as we did for any other number of decimal places.

3. How do you round off to 3 significant figures?

To round to 3 sig figs, identify the 4th sig fig is more than 5 if yes then round up else round down.

4. Do you round up at 5 for sig figs?

In case, it is 5, round the number so that it will be even. Remember that zero is considered to be even when rounding off.

Sig Fig Rounding Calculator