Accurate growth control is critical for the achievement of proportional organs during animal development and repair processes. Either extra or deficient growth rates lead to organ functional impairment. The understanding of how organs acquire, recover, and fine-tune their final size has been a long-lasting biological problem. How do organs measure their current size? This review is centered on this question through the lens of the physical properties governing cell communication mechanisms. In particular, we highlight and discuss new insight into the dynamic connections between several cellular control mechanisms that operate at different timescales to regulate organ growth and morphogenesis.