It's been a few years since my undergrad Quant course (one of the reasons why I went for organic synthesis in grad school), but my calculation gave me ~ pH 7.71.
The calculation gets fairly messy because the bicarbonate ion is amphiprotic. However, once you get above a certain concentration of the bicarbonate ion some of the values in the equation are considered negligible. From that point on the pH of a bicarbonate solution will be independent of concentratio (pH of 8.3). With that said, it will most likely be affected by dissolved CO2 in your water sample. How much? It would be hard to tell unless you had a DO meter and some other instruments.
You might get better results out of a calibration solution if you use sodium bisulfate instead. Granted, I'm not sure how readily available that is.
Hopefully someone else with more experience in that area of chemistry will be able to help out.
Do you have a pH meter available? If so, what is your pH reading for a 1 mg / L solution of sodium bicarbonate?