On the continents, sedimentary basins are generally formed by small amounts of lithospheric extension. Extension might cease because the lithospheric mantle has cooled and strengthened, or because the driving force is removed. In the former case, a relationship should exist between the maximum strain rate during extension and the final stretching factor attained. We explore how this relationship depends on the rheology of the lithospheric mantle and of the crust, as well as on sedimentation and prior rifting events. We also present strain rate information obtained by inverting subsidence data from a variety of sedimentary basins. There is evidence of a systematic relationship between strain rate and stretching factor in each basin, implying that lithospheric rheology is consistent with the rheology of olivine measured in laboratory experiments. Our data are difficult to explain if removal of the driving force governs the magnitude of stretching factors.