Macroscopic pK a evaluations relied on accuracy and correlation metrics. No method achieved a RMSE around 0.5 or lower for macroscopic pK a predictions for the challenge molecules which means methods did not achieve experimental accuracy, which is likely around 0.5 pK a units . Methods had RMSE values between 0.7 to 5.4 pK a units. Compared to the previous SAMPL6 pK a challenge, accuracy remains roughly the same. Out of all submitted methods in SAMPL7, two methods achieved a RMSE lower than 1 pK a unit (one of which was a commercially available method that we used as a reference method), while a RMSE between 1.8 and 5.4 log units was observed for the majority of methods. In terms of correlation, predictions had R 2 values ranging from 0.03 to 0.93 and only two methods achieved an R 2 greater than 0.9.