Effortlessly Calculate Your Significant Figures

What are significant figures?

Significant figures, often called sig figs, represent the digits in a number that contribute to its precision. In many cases, leading or trailing zeroes can be excluded without changing the value's accuracy (for instance, 004 is the same as 4).

When simplifying numbers by removing digits, it's important to recognize which digits are significant to maintain the number's accuracy. Rounding up or down can modify one or more of these significant figures.

How to Calculate Significant Figures?

To determine the number of significant figures in a given number, follow these three key rules:

1. Non-zero digits are always significant.
2. Zeroes between other digits are significant.
3. If a decimal point is present, trailing zeroes are significant.

Let’s break down each rule for a clearer understanding...

Significant Figures Include:

• Non-zero digits: Any digit that is not zero is always considered significant.

• Zeroes between digits: Zeroes placed between non-zero digits are significant. For example, in 205 or 3.604, the zero is significant because 205 is not the same as 25.

• Trailing zeroes with a decimal point: If there’s a decimal point, trailing zeroes are significant (e.g., 90.7500). These zeroes may seem unnecessary, but they indicate the precision of the number. For instance, 90.7500 confirms the number is accurate to four decimal places, unlike 90.75, which could have been rounded.

Not Considered Significant Figures:

• Leading zeroes: Zeroes before a non-zero digit are not significant. For example, 00200 is the same as 200, and 007 is the same as 7, meaning the leading zeroes do not affect precision.

This concept can be tricky, especially when zeroes appear after a decimal point. For instance, 0.01 kg is not the same as 1 kg, but the leading zeroes in 0.01 kg are still not significant. It’s the digit “1” that is significant, as 0.01 kg can also be written as 10 g.

• Trailing zeroes without a decimal point: Zeroes at the end of a number without a decimal point are not significant. For instance, in the number 2500, the trailing zeroes are not counted as significant figures. However, if a decimal point is present, as per rule 3, trailing zeroes become significant.

By applying these rules, you can accurately determine which digits in a number are significant, ensuring the precision of your calculations remains intact.

How Many Significant Digits Are There?

Let's look at some examples of how to calculate significant figures:

• 7 has 1 significant figure (7).
• 73 has 2 significant figures (7 and 3).
• 100 has 1 significant figure (1).
• 673 has 3 significant figures (6, 7, and 3).
• 673.52 has 5 significant figures (6, 7, 3, 5, and 2).
• 0.0637 has 3 significant figures (6, 3, and 7).
• 30.00 has 4 significant figures (3, 0, 0, and 0) with 2 decimal places.
• 0.0025 has 2 significant figures (2 and 5) with 4 decimal places.

Sig Fig Calculator Operators

Our calculator supports the following operators and functions:

• Basic arithmetic: Addition (+), subtraction (-), division (/ or ÷), and multiplication (* or ×).
• Exponentiation: Use the caret symbol (^) for exponents.
• Grouping symbols: Parentheses ( ) for grouping expressions.
• Functions: Logarithmic functions such as log and ln.

Additionally, the calculator includes a counter that displays the number of significant figures for any given calculation.