Accuracy and Precision of a Measurement

Nowadays, all scientific procedures are based on measurements. On the other side, accuracy represents the exactness of the measurement. For example, if you measure the length of any standard paper that states it is 11.0 inches long, then you will measure the length three times, and as a result, you will have three measurements: 11.1 in., 11.2 in., and 10.9 in. Such measurements are reasonably accurate as they are close to the correct value of 11.0 inches that are 2 sig figs, whereas the precision refers to the closeness of the agreement between repeated measurements. If the closeness is the same and high, then it will predict the accuracy of the measurements.

Uncertainties in Calculations

There is always going to be a chance of a definite uncertainty in any measurement of quantities. For example, if you calculate the area of a floor by measuring its length and width for sure, it will have some uncertainty as length and width measurements have some levels of doubts.

The precision of Measuring Tools and Significant Figures

A precise measuring tool can measure standards in small percentages. For example, if you use any standard ruler, it can make measurements to the nearest 0.01 millimeter.

While expressing measured values, we usually use digits that we measured at first. For example, if, with the assistance of a standard ruler, the measured length of the stick is 36.7 cm, then you cannot write it down as 36.71 cm. It happened because your measuring tool is not precise enough to measure a hundredth of a centimeter.

Use of significant figures

If you are using significant figures, then according to basic significant figures, the last digit of any measurement will be considered as the first digit with some uncertainty. Significant numbers in any calculation indicate the precision and accuracy. To determine significant figures, you just have to count the number of digits via the last digit on the right side. For instance, the above described 36.7cm has three significant figures that indicate the accuracy of the measurement. In this way, you can make your calculations precise and accurate by the use of significant figures.

The sig fig calculator by helps you in understanding how many significant figures are in a number and also assists you to find out which digits are significant in a given expression.


While dealing with significant figures, zeros have prodigious importance. The zeros that are present between two significant figures will also be considered as significant. Such as 10.053 zeros are significant. But if you have a number just like 1300, then zeros may or may not be significant depending on their style of expression. A significant figures calculator also gives the considerations to such zeros. By following significant figures, rules presence of zeros won’t disturb the accuracy and precision of your measurements.

Significant Figures in Calculations

When we are combining the measurements either manually, or with the help of a significant figure calculator, the number of sig fig in the ultimate answer will not be greater as compared to the number of significant digits in the tiniest precise measured value.

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