“If you can not measure it, you can not improve it.”

-- Lord Kelvin, 1824 - 1907



We admire your curiosity! We're a curious group too. That's why we took the time to do the research and get this right.

This quotation, and variations of it, are often attributed to iconic business writer Peter Drucker. While Drucker wrote about measuring business performance and certainly expressed similar ideas, this quotation is not his.

Nor can it be accurately attributed to Lord Kelvin.

The quotation we use on this website is concise. Kelvin’s statement was not so succinct. What Lord Kelvin wrote about measurement:

“I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.”

From “Electrical Units of Measurement”, published in “Popular lectures and addresses”, circa 1890, page 73.

So, while the short versions you see thrown around the internet make for a great pull quote, they're not quite right.

We believe in accuracy and attention to detail!