Physics Lab

The Least Count

The Least Count is the smallest value measurable by a measuring instrument.

For this ruler, the distance between two smallest lines is 1 mm.

If an object ends between two lines, we must estimate. This introduces Uncertainty. A smaller least count means higher Precision.

Least Count (LC) =

Value of 1 Main Division / Total Subdivisions

On this ruler: 1cm / 10 = 0.1 cm (1mm).

3mm Component

6.4cm Pencil

15cm Tablet

ZERO