June 29, 2026

What Is the Inflationary Gap? Definition and Formula

Inflationary gap is the amount by which an economy’s actual output exceeds its potential output, the estimated sustainable level of production.

What Is the Inflationary Gap, Exactly?

Think of potential output as the economy’s cruising speed: the level of goods and services it can produce sustainably. When actual output moves above that estimate, the positive gap indicates demand is pressing against available capacity and can add upward pressure to prices.

Economists also call this a “positive output gap.” The output gap is the difference between actual and potential output, usually expressed as a percentage of potential output. A positive figure indicates output above estimated potential; a negative figure indicates output below it.

How Is the Inflationary Gap Measured?

The inflationary gap is measured as the difference between real GDP and potential GDP, usually shown as a percentage of potential GDP.

Real GDP — gross domestic product adjusted for inflation — measures what the economy actually produced. Potential GDP is an estimate of what it could produce at full, sustainable capacity. In the US, the Congressional Budget Office (CBO) publishes a widely used estimate of potential GDP, and output-gap estimates are one input to monetary-policy analysis.

Potential GDP is estimated rather than directly observed, so economists can reach different output-gap estimates from the same economy. The inflationary gap is useful context rather than a precise real-time measurement.

CostInflation publishes category prices and city comparisons across 12 cities. The Grocery Price Calculator by City compares a custom basket across those cities.

What Causes an Inflationary Gap?

An inflationary gap forms when total demand in the economy outruns total supply at the current price level.

Several forces can contribute to the gap, often at the same time:

Strong consumer spending. Higher income or easier credit can increase purchases faster than supply expands.
Fiscal stimulus. Tax cuts or increased public spending can raise aggregate demand relative to production capacity.
Low interest rates. Cheaper borrowing can encourage spending and investment.
Rising exports. Stronger foreign demand can add pressure when domestic production is near capacity.

The common thread is demand-pull pressure: too much money chasing too few goods. This is one of several distinct mechanisms that drive prices up, and it behaves differently from cost-driven inflation. For the full breakdown of how demand-pull compares to cost-push and built-in inflation, see our guide to the Types of Inflation.

Inflationary Gap vs. Deflationary Gap: What’s the Difference?

A deflationary gap, also called a recessionary gap, occurs when actual output falls below potential output. It is associated with unused capacity, weaker demand, and less upward price pressure.

The two gaps describe opposite positions relative to estimated capacity. An inflationary gap places actual output above potential; a deflationary gap places it below potential and can coincide with idle capacity and higher unemployment.

Policy responses depend on the cause and broader conditions. Central banks may raise interest rates and governments may tighten fiscal policy to cool demand during an inflationary gap. During a deflationary gap, lower rates or fiscal support can stimulate demand. Both approaches seek to bring actual output toward sustainable capacity.

How Does the Inflationary Gap Show Up in the Prices You Pay?

An inflationary gap can add upward pressure to consumer prices, but a category price change alone does not identify its cause. CostInflation shows the resulting differences across categories and cities through Coffee Price Trends, Cost of Dog Ownership, Cost of Cat Ownership, Consumer Health Retail Goods Inflation, Menstrual Care Product Inflation, and Burger Cost by City.

How Do Policymakers Try to Close an Inflationary Gap?

To close an inflationary gap, the goal is to cool demand until actual output falls back in line with potential output.

The two main levers are monetary and fiscal policy. On the monetary side, the Federal Reserve may raise interest rates, making borrowing more expensive and tending to slow spending and investment. On the fiscal side, a government can reduce spending or raise taxes to lower aggregate demand.

These tools work with variable lags. Interest-rate changes affect borrowing, spending, investment, output, and prices over time. Tightening demand more than intended can move output below potential and raise unemployment.

National output and local prices answer different questions

The output gap is a national estimate. It describes economy-wide capacity and demand, while CostInflation’s city and category pages show current prices for specific consumer goods. What Is CPI? and What Is the Inflation Rate? explain price change across broad baskets.

Key Takeaways

An inflationary gap is the amount by which an economy’s actual output exceeds its estimated sustainable potential, a condition associated with demand-pull price pressure.
It’s measured as the difference between real GDP and potential GDP; in the US, the Congressional Budget Office publishes the most-watched potential GDP estimate, but it’s a model, not a direct observation.
Strong consumer spending, fiscal stimulus, low interest rates, and rising exports can contribute to demand exceeding available capacity.
CostInflation publishes city- and category-level price comparisons that complement national output and inflation measures.

Frequently Asked Questions

What is the inflationary gap in simple terms?

An inflationary gap is the amount by which actual output exceeds estimated sustainable potential output. It indicates demand is pressing against capacity and can add upward price pressure.

What is the difference between an inflationary gap and a deflationary gap?

An inflationary gap means actual output is above potential output and is associated with upward price pressure. A deflationary gap, or recessionary gap, means actual output is below potential and is associated with unused capacity and weaker price pressure.

What causes an inflationary gap?

It occurs when total demand exceeds available production capacity. Strong consumer spending, fiscal stimulus, low interest rates, and rising exports can contribute to that demand-pull pressure.

How is the inflationary gap measured?

It’s measured as the difference between real GDP (inflation-adjusted output) and potential GDP (sustainable output), usually expressed as a percentage of potential GDP. A positive figure indicates an inflationary gap.

Is an inflationary gap good or bad?

A positive gap can coincide with strong demand and high resource use, while a large or persistent gap can increase inflation risk. Its interpretation depends on the estimate, inflation expectations, and other economic conditions.

What is the relationship between the inflationary gap and the output gap?

The output gap is the broader term for the difference between actual and potential output. An inflationary gap is a positive output gap — when actual output exceeds potential.

How do governments close an inflationary gap?

Authorities may cool demand through monetary policy, such as raising interest rates, and fiscal policy, such as cutting spending or raising taxes. Effects arrive with variable lags, and excessive tightening can move output below potential.

Does the inflationary gap affect all prices equally?

No. A national output gap is an economy-wide aggregate estimate. Individual categories and cities can move at different rates, and city-level price indices show that variation.

How does the inflationary gap relate to the inflation rate I see in the news?

A positive output gap is one indicator of demand pressure that can contribute to inflation. The output gap compares actual and potential production; the inflation rate measures price change over time.

Can an inflationary gap exist without high inflation?

Yes. The timing and size of the price response depend on expectations, supply, productivity, and policy. A sustained positive gap raises the risk of persistent inflation without determining a fixed outcome or schedule.