The PMI, or Purchasing Managers’ Index, is a monthly economic indicator that tracks whether business conditions are expanding or contracting. It runs on a simple 0-to-100 scale, with 50 as the dividing line: anything above 50 signals growth compared to the previous month, anything below 50 signals a slowdown, and a reading of exactly 50 means conditions are unchanged. Because PMI data comes out well before GDP figures, investors, policymakers, and business leaders watch it closely as an early read on the economy’s direction.
How the 50-Point Scale Works
The PMI isn’t a percentage or a dollar amount. It’s a diffusion index, meaning it measures the breadth of change across an industry. A reading of 53, for example, tells you that more purchasing managers reported improving conditions than worsening ones. A reading of 46 means more managers saw things getting worse. The further the number moves from 50 in either direction, the stronger the signal. A reading of 55 reflects a more robust expansion than 51, and a reading of 42 reflects a sharper contraction than 48.
This simplicity is part of what makes the PMI useful. You don’t need a finance background to interpret it. Above 50 is good news for the economy. Below 50 is a warning sign. A string of months below 50 often lines up with broader economic weakness, while sustained readings above 50 tend to coincide with periods of growth.
What the Survey Actually Measures
The PMI is built from surveys sent to purchasing managers at hundreds of companies. Purchasing managers are the people responsible for buying raw materials, parts, and supplies, so they have a front-row seat to shifts in demand and supply chains. Each month, they’re asked whether conditions in several categories improved, stayed the same, or deteriorated compared to the prior month. The key areas covered include new orders, production levels, employment, supplier delivery times, and inventories.
Each of these components carries a specific weight in the final calculation. New orders and production tend to have the largest influence because they reflect real-time demand. Supplier delivery times are interpreted in reverse: slower deliveries can actually signal expansion, because suppliers get backed up when demand is strong. The weighted responses are combined into the single headline number you see reported in the news.
Manufacturing PMI vs. Services PMI
When people say “the PMI,” they usually mean the manufacturing PMI, which covers factories and goods production. But there’s also a services PMI that tracks industries like healthcare, finance, retail, and hospitality. Since services make up roughly two-thirds of the U.S. economy, the services reading arguably matters more for the overall picture. Both indexes use the same 0-to-100 scale and the same 50-point threshold, but they can move in different directions. Manufacturing might contract while services expand, or vice versa.
Some reports combine the two into a “composite” PMI that gives a single snapshot of the entire private sector. When you see PMI numbers in a headline, it’s worth checking whether the story is about manufacturing, services, or the composite figure, since each tells a different part of the story.
Who Publishes PMI Data
Two major organizations release PMI reports in the United States. The Institute for Supply Management (ISM) publishes its Manufacturing PMI and Services PMI on the first and third business days of each month, respectively. S&P Global publishes a separate set of PMI reports, sometimes called the “flash” PMI because preliminary estimates come out before the ISM numbers.
The two sets of data use slightly different survey panels and methodologies, so their headline numbers don’t always match. In most months they tell a similar story, but occasional divergences aren’t unusual. Research from ABN AMRO found that the S&P Global manufacturing PMI has performed somewhat better as a leading indicator in the post-pandemic period, though both are reasonably good predictors of manufacturing output. Most U.S. financial coverage focuses on the ISM report because of its longer track record and influence on market expectations.
Why the PMI Matters for the Economy
GDP data, the broadest measure of economic output, is released on a quarterly basis with a significant lag. The PMI fills that gap by offering a monthly, near-real-time signal. Research from the Federal Reserve Bank of St. Louis found a correlation coefficient of 0.75 between the U.S. manufacturing PMI and GDP growth over a multi-year period. That’s a strong positive relationship, though not a perfect one. The researchers also found that when the PMI was above 50, GDP growth was more often positive than negative.
Financial markets react to PMI releases because they shape expectations about corporate earnings, consumer spending, and interest rates. A surprisingly strong PMI reading can push stock prices higher and bond prices lower as traders price in faster growth. A weak reading can do the opposite. Central banks also factor PMI trends into their decisions about raising or cutting interest rates, since persistent expansion or contraction in the index helps confirm whether the broader economy is heating up or cooling down.
Reading a Real PMI Report
A PMI report doesn’t just give you the headline number. It breaks results down by industry, which is where the detail gets useful. The ISM’s March 2026 Manufacturing PMI, for instance, came in at 52.7, up slightly from 52.4 in February. That headline number showed continued expansion, but the industry-level data told a more nuanced story. Thirteen manufacturing industries reported growth, led by printing, primary metals, and transportation equipment. Three industries reported contraction: plastics and rubber products, furniture, and food and beverage.
This kind of breakdown helps you understand where strength and weakness are concentrated. A headline reading of 52 driven by broad-based growth across many industries is a healthier signal than a 52 driven by a surge in just one or two sectors while others contract.
PMI Reports Outside the United States
PMI surveys run in more than 40 countries, making the index one of the most widely tracked global economic indicators. S&P Global publishes PMI data for the eurozone, the United Kingdom, Japan, China, and many emerging markets. The same 50-point threshold applies everywhere, so you can compare readings across countries at a glance.
The Federal Reserve Bank of St. Louis found that China’s GDP growth rate is more sensitive to PMI changes than the U.S. growth rate. An increase from 50 to 55 in China’s PMI could push predicted GDP growth from 5 percent to more than 15 percent, while a similar jump in the U.S. PMI would produce a much smaller effect. This difference reflects the varying structures of each economy, but it underscores why global investors watch PMI readings from major economies around the world, not just their home country.
How to Use PMI as an Investor or Worker
You don’t need to trade stocks to find PMI data useful. If you work in manufacturing, logistics, or any supply-chain-adjacent field, a falling PMI can be an early heads-up that hiring may slow or overtime hours could shrink. If you run a small business that sells to manufacturers, a rising PMI suggests your customers may be placing larger orders soon.
For investors, the PMI’s value is as a confirmation tool rather than a standalone signal. One month of data can be noisy. A trend over three to six months is far more meaningful. Watching whether the PMI is trending toward or away from the 50-point line gives you a sense of momentum. Pairing that trend with employment data, consumer spending figures, and corporate earnings reports gives a more complete picture than any single indicator can provide on its own.