ABOUT
A grid calculation you can inspect.
Binspan answers one practical question: where are the nonnegative frequency bins for this sampling rate and length?
It calculates spacing, endpoint and timing quantities, then optionally finds the represented centre closest to one target. Neighbours and endpoints are a bounded view of that same grid. The tool does not analyse signals or run an FFT.
Exact fractions make the arithmetic inspectable. The odd-length endpoint and the lower-index tie rule are stated explicitly, because silently assuming either can change how a result is read. Original examples separate record duration from final-sample offset.
The calculator is free and needs no account. Advertising may support it later, subject to actual host setup and appropriate consent. This release has no active advertising, analytics or consent-platform loaders. Free access does not depend on an advertising decision.