You will usually get a manual with your product, which is going to contain information on how much to inflate your SUP or kayak. For most products, the recommended range is somewhere between 10 and 15 PSI. Many of the pumps we’ve reviewed operate in this range (or higher) so you have plenty of options to choose from.
As we’ve mentioned, the pressure where your SUP board is going to burst is much higher than the optimal pressure. This doesn’t mean that you should over-inflate your board hoping you will get better results, as the rigidity and performance are going to stay the same.