PULCON (Pulse Length-Based Concentration Determination) is a powerful, versatile, non-invasive, and accurate technique for measuring solution concentrations via routine NMR spectroscopy. It is particularly useful for preparing accurate solutions of compounds for biological assays, and avoids weight-based errors caused by contaminants (e.g. moisture). This article provides an introductory guide for biological and medicinal chemists, and highlights the diversity of applications.