What is Relative Standard Error?
Relative Standard Error (RSE) expresses the standard error of an estimate as a percentage of the estimate itself. It makes it easier to compare the precision of estimates that are on very different scales.
The formula
RSE = (Standard Error / Estimate) × 100%. A smaller RSE means the estimate is more precise relative to its size. Many statistical agencies use a general rule of thumb that an RSE of 25% or lower suggests reasonably reliable data, though thresholds vary by field and application.
This calculator is for general educational and planning use; specific fields may apply their own reliability thresholds.
Last reviewed August 2026