In estimating blood loss, how many millilitres is equivalent to 1 gram?

• A. 0.1 ml
• B. 1 ml
• C. 10 ml
• D. 100 ml

Answer: (B)

Estimating blood loss often uses a gravimetric approach, relying on the fact that blood density is about 1 g per mL. That means 1 gram of blood has a volume of roughly 1 milliliter. So the correct equivalent is 1 mL. In practice, you might weigh soaked gauze or swabs; a 1-gram increase in weight roughly equals 1 mL of blood loss. If you wanted more precision, whole blood density is around 1.06 g/mL, but for quick estimates the 1:1 rule is standard. The other values would significantly over- or under-estimate the volume because they imply much larger or smaller amounts of blood per gram.