How many litres of blood does the heart pump per day?
Guess before you scroll — the answer is below
The answer
7,500 litres
Roughly 7.5K.
The heart pumps about 7,500 litres of blood a day — enough to fill a small swimming pool every fortnight. It does this with a muscle the size of a fist, without stopping, for a lifetime.
How to get close to this number
Three numbers you already have give the answer. The body holds about five litres of blood, the heart pushes out roughly that much every minute at rest, and a day has 1,440 minutes. Multiply and you land in the thousands of litres. Every input is either common knowledge or derivable from the companion question on this site.
The counterintuitive part is that the same blood circulates repeatedly. The heart is not pumping thousands of litres of different fluid; it is moving the same five litres round a loop hundreds of times a day. Any throughput figure for a closed system measures circulation rate, not quantity, and confusing the two makes the number sound impossible.
The comparison in the explanation makes it physical: enough to fill a small swimming pool every fortnight, done by a muscle the size of a fist, continuously, for a lifetime with no maintenance interval. The output figure is really a durability figure, which is why it is quoted by cardiac charities rather than by physiologists.
Where this number comes from
| Source | British Heart Foundation |
|---|---|
| Figure refers to | 2023 |
| Last checked | |
| Unit | litres |
Numbers move. If this one has drifted from its source, let us know.
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