We often get this question: "What parachutes make good drogue parachutes?" We're here to help you out, so here's our answer: The smaller Classic Elliptical parachutes make good drogue parachutes for our large Iris parachutes. Alternatively, use these alone in your smaller rockets. They are also good choices for pilot parachutes to help drag the deployment bag off the large main parachute.
As a good rule of thumb, the drogue or pilot parachute is 1/4 to 1/5 the diameter of your main parachute. When using Rocksim or another calculator, the descent rate shown will be higher than you will get in real life due to the drag of the airframe. As such, choose a smaller size to actually get the descent rate the simulation tells you.
If you have questions, be sure to contact us.