Sig Fig Calculator | The Best Significant Figures Calculator Online That Shows The Correct Value

Significant Figure

Sig Fig Calculator


Decimal Notation:

No. of Significant figure:

No. of Decimal:

Scientific Notation:


#1 (The original number has sig figs)

#2 Rounded to significant figure


Sig Fig Calculator | The Best Significant Figures Calculator Online That Shows The Correct Value

Significant Figures Calculator
Significant Figures Calculator

Sig Fig Calculator | The Best Significant Figures Calculator Online: The number of significant figures arising from this is essentially the number of figures considered to have a degree of reliability. Are you wondering how to calculate the numbers of significant figures? If so, then it is very important that you use this sig fig calculator as we are going to give you online software to use and get results.


The digits that have meaning about a calculated or given value are referred to as Significant Figures of a number. When conducting arithmetic, it’s critical to account for Significant Figures correctly so that the resulting answers accurately reflect numbers of computational importance or meaning. There are three rules for determining the number of significant figures in a number. There are also rules for calculating how many digits can be used in numbers calculated by addition/subtraction, multiplication/division, or a combination of these operations.

The number of relevant figures in a measured quantity is determined using the following rules:

  1. Every non-zero digits are significant:

Hopefully, this law is self-evident. If you calculate something and the instrument you use (ruler, thermometer, triple-beam balance, etc.) gives you a number, you’ve made a measurement decision, and the act of measuring gives that numeral (or digit) meaning in the total value you get. As a result, a number like 26.38 has four significant numbers, while 7.94 has three. The issue arises when numbers such as 0.00980 or 28.09 are used. 1.234 g has four significant numbers, while 1.2 g has just two.

  • Zeroes between nonzero digits are significant:

If you had a number like 406, the 4 and 6 are significant according to the first rule. However, you had to decide on the ten’s position to make a measurement decision on the 4 (in the hundred’s place) and the 6 (in the unit’s place). Hundreds and tens will be marked on the measurement scale for this figure, with an estimate made in the unit’s position. There are four significant figures in 1002 kg, and three significant figures in 3.07 ML.

  • Zeroes to the left of the first nonzero digits are not significant;

They merely signify the decimal point’s position: 0.001o C has just one significant number, while 0.012 g has two.

  • In a number, the zeroes to the right of the decimal point are significant:

0.023 mL has two significant numbers, while 0.200 g has three.

  • When a number ends in zeroes  that are not to the right of a decimal point, the zeroes aren’t always significant:

190 miles could be two or three significant numbers, while 50,600 calories could be three, four, or five significant figures. The last rule’s possible uncertainty can be avoided by using standard exponential, or “scientific,” notation. For example, depending on whether three, four, or five significant figures are correct, 50,6000 calories may be written as: 5.06*104 calories (3 significant figures) 5.060*104 calories( 4 significant figures) or 5.0600*104 calories (5 significant figures).


The number of significant figures in a calculation, such as 2.531, is equal to the number of digits known with reasonable certainty (2, 5, and 3) plus the last digit (1), which is an estimation or approximation. The number of significant figures increases as the accuracy of the equipment used to make a calculation improves.

When several measurements with varying degrees of accuracy and precision are combined, the final result can only be as accurate as of the least accurate measurement. This principle can be expressed as a basic addition and subtraction rule: When adding or subtracting measurements, the answer may only have as many decimal places as the least accurate measurement.

The use of significant figures in multiplication and division follows the same principle: the final result can only be as precise as the least accurate calculation. However, we count the significant figures in each measurement rather than the number of decimal places in this case: When measurements are multiplied or divided, the answer may only have the least accurate measurement as a significant number.

Let’s calculate the cost of the copper in an old penny that is pure copper to demonstrate this law. Assume the penny weighs 2.531 grams, is essentially pure copper, and copper costs 67 cents per pound. We can start with grams to pounds.

When a calculation yields a result of so many significant numbers, it must be rounded off. In measurement, the last decimal place will contain up to ten digits. Underestimating the answer for five of these digits (0, 1, 2, 3, and 4) and overestimating the answer for the other five is one method of rounding off (5, 6, 7, 8, and 9). The following is a summary of this approach to rounding off.

If the digit is less than 5, drop it and leave the rest of the number unchanged. As a result, 1.684 becomes 1.68. If the digit is 5 or higher, drop this digit and add 1 to the digit before it. As a result, 1.247 becomes 1.25.

An exact number arises from counting something or a specific unit. It is thought that they have an infinite number of significant figures. When counting eggs in a dozen, there should be exactly 12 without any doubt. As a result, the number of significant figures in answer 12 is infinite. The number of significant figures in the answer is calculated by the other numbers in the problem when using an exact number in a calculation.

Our significant figures calculator has two modes of operation: it can perform arithmetic operations on several numbers (for example, 4.18 / 2.33) or it can simply round a number to the number of significant figures you want. We may calculate sig figs by hand or with the significant figures counter by following the above rules.

Let’s say we’ve got the number 0.004562 and need two important figures. After that, we round 4562 to two digits, yielding 0.0046. We’ll now look at an example that isn’t a decimal. Let’s say we want 3,453,528 to four decimal places. We simply round the total to the nearest thousand, resulting in a total of 3,454,000.

The same laws apply in all cases. Using E notation, which replaces x 10 with either a lower or upper case letter ‘e’, to enter scientific notation into the sig fig calculator. The number 5.033 x 1023, is equal to 5.033E23 (or 5.033e23). The E notation representation of a very small number, such as 6.674 x 10-11, is 6.674E-11 (or 6.674e-11).

When dealing with estimation, the number of significant digits should not exceed the sample size’s log base 10, and rounding to the nearest integer should be avoided. If the sample size is 150, the log of 150 is approximately 2.18, so we use two significant figures.

1) All nonzero digits are significant.

2)  With two special cases zeros are significant as well:

  1. Zeros before the decimal point.
  2. Zeros after the decimal point and before the first nonzero digit.

3)  An ambiguous case is the Terminal zeros before the decimal point in amounts greater than one.

1.         Start counting for significant figures.  A non-zero digit on the first.

2.         STOP counting for significant figures. On the non-zero last digit.

3.         Non-zero digits are STILL significant.

4.         Zeroes in between two non-zero digits are significant. All the remaining zeroes are insignificant.

1. Start counting for significant figures. A non-zero digit on the first.

2. STOP counting for significant figures. On the very last digit (regardless last digit is a zero or non-zero).

3. Non zero digits are significant.

4. Any zero is still significant since the first non-zero digit. The zeroes preceding the first non-zero digit are insignificant.

1) Integers:  

The zeros toward the end of an integer don’t count as the significant. 

If you have $1000 in your wallet, it could vary from over $500 to under the $1500. Then, the precision of 1000 is to one significant figure.

If you have $1100 in your wallet, it could vary from over $1050 to under the $1150.  Then, the precision of 1100 is to two significant figure.

If you have $1110 in your wallet, it could vary from over $1105 to under the $1115.  Then, the precision of 1110 is to three significant figure.

If you have $1111 in your wallet, it could vary from over $1110.5 to under the $1111.5.  Then, the precision of 1111 is to four significant figure.

Note: As you may have noticed, the last zeros of the integer number does not count as the significant.


1) 507: It has 3 significant figures.

2) 50,700: It has 3 significant figures.

3) 1,030,700: It has 5 significant figures.

2) Decimals

All figures are the significant except the leading zero (0) s after its decimal point for a decimal numbers that are less than 1. For instance 0.623 kg is less than 1 and has 3 sig. figs. This is identical to 623 grams.

Suppose we have 0.000623 kg instead. The three zeros before 623 but after the decimal point are not considered to be significant. This is equal to 623 milligrams and has three sigs. figs.

Now, if the decimal number is greater than 1, for example, 6,789 kg, it has 4 significant figures. This is identical to 6,789 grams and has four significant figures.

Assume now we have 8.0235kg now, which can be written as 8.023.5 grams. It has got 5 significant figures.

Here, the zero after its decimal point, however leading to the 235 part, considers as significant in light of the fact that the number is greater than 1 (one) and has the non decimal part that is 8 (eight).


1) 0.13070kg: It has 5 significant figure.                

2) 1.07000cm: It has 6 significant figure.                           

3) 0.0007cm: It has 1 significant figure.                               

4) 22.0000cm: It has 6 significant figure.                             

50.000009cm: It has 1 significant figure.                        

6) 1.0400700cm: It has 8 significant figure.                        

7) 10.407005cm: It has 8 significant figure.                      

8) 100.000, 0020cm: It has 10 significant figure.                   

9) 100,000,000.0cm: It has 10 significant figure.                    

10) 100,000,000,000cm: It has 1 significant figure.                    

I) For multiplication, division, raising to a power, or taking any roots,

a) The final result must be rounded to the same number of significant figures. if the given numbers have the same number of significant figures., 

b) The final result must be rounded to the lowest number of significant figures.  if the given numbers have different numbers of significant figures., 

For instance, if 12 (2 significant figures.) is duplicated by 25 (likewise 2 significant figures.), the subsequent number is 300 however should be written in a form that shows it is good to 2 significant figures. You may either put a small bar on the zero after 3, or compose the number as 3.0×102.

As another example, if 12.0 (3 significant figures.) is multiplied by 25 (2 significant figures.), the total must be written in two significant figure again as 300 with a tiny bar on the zero after 3 or as 3.0x102.

II) The precision of the numbers added or subtracted is significant for addition or subtraction.

Example, if the mass of the screw is measured with a scale that is good to one gram of precision, and the mass of the corresponding nut is measured with another scale that is good (or precise) to one milligram (1000 times better precision), and if we want to add the mass of the two, the high precision of the nut mass is useless compared to the low precision of the bolt mass!


 Mass of the bolt= 8 grams (8000milligrams, 1 significant figure.)

Mass of the nut= 0.675 grams (675milligrams 3 significant figures.)

Total= 8.675 gms

However, the total may not be written as 8.675grams!  First, we should round off 0.675milligrams and that will be 1 gm. After that addition is done and total mass will be 9 gms i.e. (9000mg). Thus, it ends up with 1 sig fig.


1)  75m x 4m = 3×102m2 (1 significant figure.)         

2) 75cm x 4.0cm =3.0x102m2 (2 significant figure.)         

3) 0.750 ft x 4.000 ft =3.00ft2 (3 significant figure.)  

4) 7500 in. x 0.004 in. = 3.0x101 in2 (2 significant figure)      

5) 125m / 25s = 5.0m/s (2 significant figure.)              

6) 80f t / 16s =5ft/s (1 significant figure.)   

7) 33,333mi / 3h =10,000 mi/h (1 significant figure.),     

8) 3750km / 2.50s =1.50×103 km/s (3 significant figure.)   

9) (25m – 16m) / 0.0003s = 30000 m/s (1 significant figure.)

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