On average stem length will be about 18-19 inches. Roses will typically fall right in this range, but again, this depends on the rose variety and bloom size.
The flower stems will often be slightly different lengths when they arrive. We do this to keep the buds from smashing into each other during shipping. When the VivaRoses arrives we recommend you cut all the stems to the same length and proper height for the vase for the most attractive arrangement!