It is commonly stated that a large share of Finnish regions are shrinking in terms of their population and local economy, which naturally poses challenges for balanced regional development. However, and rather surprisingly, there has been relatively little methodological discussion in Finland on the measurement of shrinkage: how to determine whether a region is shrinking or not? The main aim of this paper is to analyse shrinkage through spatio-temporal indicators and to discuss the variety and complexity of the task. Empirically the paper utilises three commonly used indicators (population, employment, and housing vacancy), three different analysis periods (long, medium and short) and five different spatial scales (regions, sub-regions, municipalities, postal code areas and grids). The results underline how volatile the results are depending on these three choices (indicator, analysis period and spatial scale) when aiming at determining, which of the regions under investigation are shrinking. Depending on the indicator choices and analysed spatio-temporal scales, different shares of Finnish regions can be identified as shrinking. Thus, care is needed when considering which indicator(s), analysis periods and spatial scales are selected for conducting statistical analyses on shrinkage particularly if the results are applied in policies.