Resistor Tolerance Range

Formula

Description

Every resistor has a tolerance band that specifies the range within which the actual resistance may fall. A 10 kΩ resistor with 5% tolerance could measure anywhere from 9.5 kΩ to 10.5 kΩ. The forward result returns the worst-case (maximum) value R × (1 + tol). For critical circuits such as precision voltage references, instrumentation amplifiers, and Wheatstone bridges, tight tolerance (0.1% or better) is essential. Standard tolerance bands are 20% (M), 10% (K), 5% (J), 2% (G), 1% (F), 0.5% (D), 0.25% (C), 0.1% (B).

Variables

• R — Nominal resistance (Ω)
• tol — Tolerance as a ratio (e.g., 0.05 for 5%)

Practical Notes

Enter tolerance as a ratio (0.01 for 1%, 0.05 for 5%) or use the % unit selector. The worst-case scenario in a voltage divider occurs when one resistor is at +tol and the other at −tol. For Monte Carlo analysis, resistor values typically follow a Gaussian distribution truncated at the tolerance limits.