Calculate Elastic Modulus from Shore A Durometer
Although there is no exact correlation between elastic modulus and shore A durometer, there are several very close empirical relations, many of which are specified in this whitepaper from Dow. Specifically, the Ruess method correlates very well for shore A values between 30 and 60 (of particular interest to instron mechanical testing right now, since those are the shore values of the parts produced by ProtoLabs).
The Ruess relation is as follows:
lg(E) = 0.0235S - 0.6403Where lg is base 10 log, S is shore A durometer value, and E is the elastic modulus in MPa.
The form below is a quick way to calculate the elastic modulus based on this relationship, given shore A durometer.