According to the label, each packet of Splenda "sweetens like two teaspoons of sugar". Each packet weighs 1.0 grams.

The bulk Splenda, as you are using, says that it "measures, sweetens and pours cup for cup just like sugar". Each teaspoon weighs 0.5 grams.

So if the recipe calls for one packet, that's 2 teaspoons of the bulk.