This is a new Minerazzi tool, available now at

http://www.minerazzi.com/tools/t-p-effect-size/estimator.php.

This tool estimates t-scores from p-values and vice versa for a given number of degrees of freedom υ. Just enter a (t,υ) or (p,υ) pair and this tool will solve for the missing term.

The tool also estimates the statistics that one would obtain if the computed estimates correspond to a set of paired variables (x, y), or to effect sizes from any two samples of same sizes (n1 and n2); i.e. samples with same degrees of freedom (υ1 and υ2).

The tool’s page lists some interesting exercises and good references for effect size conversions and meta-analysis in general. Enjoy it!