Question

How do you calculate the volume of blood your heart pumps in an hour?

Answer 1

`T = 60 * V * r`, where `T` is the total in an hour, `60` due to minutes in an hour, `V` is the volume of blood per beat, and `r` is the resting heart rate in beats per minute.

Explanation:

A human (~adult) heart pumps between 60 and 90ml of blood each contraction, so a good average would be anywhere from `70` to `80ml` to use in calculation. I'll use `75`, though it would vary with age, person, and instantaneous exertion, presumably.

Take your resting heart rate in beats per minute. Take it a few times and find the average for the most accurate value.

Do the calculation

`T = 60 * V * r`,

where `T` is the total blood pumped, `V` is the volume per pump (`75` in this approximation, `r` is resting heart rate and `60` is for the number of minutes you want.

With units, this is

`T ml = 60min * V(ml)/(beats) * r (beats)/(min)`,

so the `min` and `beats` units cancel, leaving only `ml`.

Say your resting heart rate is `80 (beats)/(min)`, then the total blood pumped in one hour is approximately

`T approx 60 * 75 * 80 = 360,000ml = 360L`