The calculation already factors in that there are only two PC's. If it were a four person 1st level party, each of them would have only gotten 188 xp.
Keep in mind that PC's reach 2nd level at a mere 1,000 xp. An XP award of 375 is a LOT of XP for first level characters; it's more than 1/3 the way to the next level. Getting to 2nd level is supposed to take more than 13 'equal level' encounters (ie - a first level character should routinely get about 75 xp per encounter).
If you don't mind a little self-promotion on my part, I have written a campaign log that many say provides great DM insights. Maybe reading it will help you as you start your journey as a DM. Good luck on your game!