Equations in this panel (except O2 capacity) assume that Hb carries 1.36mL of O2.
Some formulas use the constant 0.003, MediCalculator™ uses 0.0031.

CaO2 depends on SaO2 and hemoglobin, 1 g of hemoglobin carries 1.36 mL of O2 (1.34mL - 1.39mL).
Oxygen content equals the oxygen combined (with hemoglobin), usually ~ 97% and the Oxygen dissolved (in plasma), usually ~ 3%.