This site has a spirometry calculator:
I am not sure how it works really, but maybe would help.
Actually your numbers look pretty good..A FEV1 and FVC of >80% is considered normal. What is interesting is that your FEV1/FVC ration is near 100%. That value is used to see if there is obstructive (like COPD) disease versus restrictive (like pulmonary fibrosis). Obstructive disease is seen with a FEV1/FVC ratio of less than 80%..so it looks like there is no real obstruction. But, I am not a doctor, so please take what I say lightly...just a fellow respiratory patient and ex nurse with her share of PFT's. Of course the best thing to do (which you are doing in a few weeks) is to see your doc and go over the results as he or she is familiar with your medical history and situation. Congrats on remaining tobacco free, I am sure that has helped. Hope this helps...Sunny