Significant Figures in a Product Calculator

About this calculator

When multiplying or dividing measured quantities, the result can't claim more precision than the least-precise measurement that went into it. The standard rule of significant figures for multiplication and division states that the answer should be rounded to the same number of significant figures as the operand with the fewest — unlike addition and subtraction, which instead go by decimal places.

This calculator takes two values and an operation, identifies the significant figures in each operand, and returns the correctly rounded result along with the sig-fig count that governs it. It's a core skill taught in chemistry and physics lab courses, where reporting a calculated result with false precision — more digits than the original measurements actually justify — is a common and easily avoidable mistake in lab reports.