# Significant Figures Calculator

On this page, we'll show you how many significant figures are in a number or mathematical formula/expression, and give you some useful information and facts about how to calculate it.

## How to Use This Significant Figures Calculator

The calculator is pretty straightward and easy to use. Just enter number or mathematical expression in the text box and click "Calculate Sig Figs".

We will then list out the significant figures in the expression, along with the steps taken to calculate them, and different significant figure roundings as necessary.

This calculator uses the following sig fig rules:

1. All non-zero numbers are significant. The number 47.4 has THREE significant figures because all of the digits present are non-zero.
2. Zeros between two non-zero digits are significant. For example, 4098 has FOUR significant because the zero is between two non-zero digits, 9 and 8.
3. Leading zeroes are not significant. Leading zeros are considered to be placeholders. The number 0.42 has only TWO significant figures. 0.0042 also has TWO significant figures.
4. Trailing zeros to the right of the decimal are significant. For example, 97.00 has FOUR significant figures. This is because scientists or workers who require precision will know that 97.00mm is different to 97mm because 97.00mm is accurate to the nearest 1/100th millimeter.
5. Trailing zeros in a whole number with no decimal are not significant. 970 has TWO significant figures because the trailing zero is not after a decimal and is therefore not a significant value.
6. Exact numbers have an infinite number of significant figures. Take the example of the number 2. 2 = 2.00 = 2.000 = 2.00000 and so on. So if we have a number like 2000.4, based on rule 2 above it has FIVE significant figures. If we want to round it down to four significant figures, we know 4 is less than 5, so the answer to FOUR significant figures is 2000.
7. For a number in scientific notation: N x 10x, all digits comprising N ARE significant by the first 6 rules; "10" and "x" are NOT significant. 7.08 x 106 has THREE significant figures: "7.08". "10" and "6" are not significant. This provides the opportunity to change the number of significant figures in a value by manipulating its form. For example, let's try writing 1100 with THREE significant figures. By rule 6, 1100 has TWO significant figures; its two trailing zeros are not significant. If we add a decimal to the end, we have 1100., with FOUR significant figures (by rule 5.) But by writing it in scientific notation: 1.10 x 103, we create a THREE-significant-figure value.

## What are Significant Figures?

Significant figures, also known as sig figs for short, are the meaningful digits present in a given number.

Leading or trailing zeroes can often be removed, and the number will remain accurate, although there are sometimes differing significant figure rules depending on your use.

## Sig Fig Calculator Operators

You can use a number of different operators and functions with our calculator, and we may add more over time:

• Basic arithmetic: Addition (+), subtraction (-), division (/ or ÷), and multiplication (* or ×)
• Exponent (^) and ×10(n)
• Grouping symbols: right and left parantheses brackets ()
• Functions: Log ( log10(n) ), ln ( loge(10) )