# 40 Pounds in Kilograms

How many kilograms are in 40 pounds? The short answer is 18.14059. If that's what you're after, thanks for stopping by. If you'd like to know how we got that answer, read below.

## How to convert from pounds to kilograms

You can get a pretty good approximation of how many kilograms are in a number of pounds by dividing the weight in pounds by 2.205. That's what we're doing here, and then rounding to no more than 5 decimals. If you want a more accurate answer you can divide by 2.204622622 and not round the result. But for us and the examples here the rounding gives us a close enough answer.

In this case we're going to take 40 and divide by 2.205 to get the number of kilograms.

$$ \LARGE \begin{align} 40 \text{ pounds} &= \text{? kilograms} \\ &= 40 \text{ pounds} \div 2.205 \\ &= 18.14059 \text{ kilograms} \end{align} $$

You can also multiply by the reciprocal of 2.205 which is about 0.4536 and you should get about the same result.

$$ \LARGE \begin{align} 40 \text{ pounds} &= \text{? kilograms} \\ &= 40 \times 0.4536 \\ &= 18.14059 \text{ kilograms} \end{align} $$

## The Midnight Rule

I don't know if this is officially called the midnight rule for converting weights, but I learned it in EMS school as a quick and easy way to convert from pounds to kilograms when you're out on a call at midnight and your brain is exhausted.

Instead of memorizing either of the two conversion factors above, you first divide the number of pounds in half and then subtract 10%, or multiply by 90% like we're going to do below. It works out the same as dividing by 2.2 which is usually close enough.

$$ \LARGE \begin{align} 40 \text{ pounds} &= \text{weight in kilograms} \\ &= ( 40 \div 2) \times 90\% \\ &= 20 \times 90\% \\ &= 18.00 \text{ kilograms} \end{align} $$

It's not exact, but it's probably close enough for most needs.

## Pounds to Kilograms Calculator

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