The gap between the average savings account and a competitive one is not a rounding error. This cluster makes the size of that gap measurable.
1 calculators
The comparison baseline here is the FDIC's National Rate for savings, published monthly as part of its National Rates and Rate Caps release. It is a deposit-weighted average across all insured institutions, which is why it sits far below the best advertised offers — and why the difference is worth calculating rather than assuming.
Each calculator in this cluster states its formula, ships with worked examples that were checked against a known answer by an independent second implementation, and lists the primary source and retrieval date behind every external figure. The full method is described on the methodology page.