Postpartum hemorrhage (PPH) is one of the most common causes of mortality in obstetrics worldwide. The accuracy of estimated blood loss is a priority in determining appropriate treatment. Will the additional use of a visual aid improve physicians' accuracy in estimating blood loss compared to the use of a collector bag and baby scale alone? Simulation training sessions created three vaginal delivery scenarios for participants to estimate volumes of blood loss: firstly, using only a collector bag and a baby weight scale and secondly, adding a visual aid depicting known volumes of blood. The primary endpoint was to determine if participants could accurately evaluate blood loss within a 20% error margin. The addition of the visual estimator resulted in overestimation of blood loss. The rates of participants' estimations were significantly more accurate when using the collector bag with the baby weight scale without the addition of the visual aid; 85.5% versus 33.3% (p < 0.01) for 350 mL, 88.4% versus 50.7% (p < 0.01) for 1100 mL and 88.4% versus 78.3% (p < 0.01) for 2500 mL, respectively. Additional use of a visual aid with a collector bag does not seem to be useful in improving the accuracy in the estimation of blood loss.