If you can't measure it, you can't improve it
When setting goals or trying to improve performance
Also known as: “You can't improve what you don't measure”; “What gets measured gets managed”; “If you can't measure it, you can't manage it”
What Does “If you can't measure it, you can't improve it” Mean?
This management principle emphasizes the importance of quantifying your objectives and progress. Without concrete metrics, you're operating on assumptions and feelings rather than facts. Measurement provides clarity, accountability, and a clear path to improvement.
Origin and History
The saying is very often attributed to management writer Peter Drucker, but it has not been found in his books. It echoes Lord Kelvin, who said in an 1883 lecture that 'when you can measure what you are speaking about, and express it in numbers, you know something about it'. Interestingly, the quality pioneer W. Edwards Deming warned against the strict version, writing that 'it is wrong to suppose that if you can't measure it, you can't manage it - a costly myth' (The New Economics, 1993).
Examples
- Fitness: logging your runs shows whether your pace is actually improving or just feels like it.
- Business: tracking how long support tickets take to resolve tells you whether a new process helped.
- Personal finance: a month of tracking spending usually reveals where the money really goes.
- Websites: measuring page load time before and after a change shows whether the change worked.
What Happens When You Break It
Without measurement, you waste time on ineffective strategies, miss opportunities for optimization, and can't demonstrate value or progress. Teams become misaligned, and resources are allocated inefficiently based on opinions rather than data.
Benefits of Following This Rule
Measuring performance enables continuous improvement, helps you prioritize efforts effectively, provides accountability, allows you to celebrate wins with concrete evidence, and makes it easier to replicate success.
Frequently Asked Questions
Who said 'If you can't measure it, you can't improve it'?
It is commonly attributed to Peter Drucker, but there is no confirmed source in his writings. The idea goes back at least to Lord Kelvin's 1883 remarks on measurement.
Is the saying always true?
No. Some important things - trust, morale, creativity - are hard to measure but can still be improved. And when a number becomes a target, people may game it (Goodhart's law). Measure what matters, and use judgment for the rest.
What is the difference between this and 'what gets measured gets managed'?
They express the same idea: attention follows measurement. The second version is often used as a warning that people will focus on whatever is measured, even if it is the wrong thing.