Okun's Law Calculator (unemployment gap → output gap)

Understanding the Okun's law calculator — concept and principle

Okun's law is a rule of thumb linking unemployment and economic output: when unemployment is above its natural rate, output tends to be below its potential. This calculator estimates the output gap from the unemployment gap and, if you enter potential GDP, the implied actual GDP.

Unemployment one point above its natural rate goes with output about 2% below potential: 29,400 instead of 30,000.

How it is calculated

Gap version: (Y − Y*) ÷ Y* = −β × (u − u*)

u = actual unemployment rate; u* = natural rate.
β = Okun coefficient, the percent of output lost per point of excess unemployment.
Output gap (%) = −β × unemployment gap.
Estimated actual GDP = potential GDP × (1 + output gap).
The reverse view: unemployment change per 1% output gap = 1 ÷ β.

The principle

When firms produce less, they need fewer workers, so unemployment rises. But output falls by more than employment, because firms also cut hours, workers leave the labour force and productivity dips in downturns. Arthur Okun observed this pattern in US data in 1962. Later estimates, such as a Kansas City Fed study, found that a 1% shortfall in output is associated with unemployment about 0.5 point above its full-employment level, which corresponds to β ≈ 2. The coefficient is a statistical average, not a physical constant.

Worked example

Default inputs: unemployment 5.5%, natural rate 4.5%, potential GDP 30,000, β = 2.

Unemployment gap = 5.5 − 4.5 = 1 point.
Output gap = −2 × 1 = −2%.
Estimated actual GDP = 30,000 × (1 − 0.02) = 29,400.
Output below potential = 29,400 − 30,000 = −600.
Unemployment change per 1% output gap = 1 ÷ 2 = 0.5 point.

Each point is the calculator re-run with only “Actual unemployment rate (%)” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

Actual unemployment rate (%)	Output gap
1.38	6.25%
2.75	3.5%
4.12	0.75%
5.5	-2%
6.88	-4.75%
8.25	-7.5%
11	-13%

How to read the result

A negative output gap means the economy is producing less than it could; such slack usually goes with low inflation pressure. A positive gap means it is running above potential. Because β differs between countries and over time, try a range (for example 1.5 to 3) to see how sensitive the result is.

Common mistakes

Treating Okun's law as an exact law rather than an empirical regularity.
Using a coefficient estimated for one country for another.
Mixing the gap version with the difference version, which relates changes in unemployment to GDP growth.
Assuming the natural rate and potential GDP are known precisely.

Keep in mind: Okun's coefficient varies and potential GDP and the natural rate are estimates. Use the result for learning and rough reasoning, not forecasts.

Frequently asked questions

What is the Okun coefficient?

The number of percent of output associated with one point of unemployment above its natural rate; about 2 in many US estimates.

Does Okun's law still hold?

The relationship remains visible in data but shifts over time and across countries.

What is the difference version of Okun's law?

It links the change in unemployment to how far GDP growth is above or below its normal rate.

Sources: Okun, A. M. (1962). Potential GNP: Its Measurement and Significance. Proceedings of the Business and Economic Statistics Section, American Statistical Association. · Knotek, E. S. (2007). How Useful Is Okun's Law? Federal Reserve Bank of Kansas City Economic Review.

Checked 9 Nov 2026. E. S. Knotek II, “How Useful is Okun’s Law?”, Economic Review, Federal Reserve Bank of Kansas City, Fourth Quarter 2007 (gap and difference versions; about 0.5 point of unemployment per 1% output gap).

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