Proto LabsWBO:PRLB +1.23%66 Days Inventory is 17.52 as of Mar. 2026, which is 1% below its 10-year median of 17.64. GuruFocus rates WBO:PRLB with a GF Score™ of 66/100 and a GF Value™ of €37.76 (Significantly Overvalued). The stock has 7 warning signs investors should review. Among 2,969 Industrial Products companies, Proto Labs ranks better than 97.34% on this metric.
Days Inventory is also known as Days Sales of Inventory (DSI). Proto Labs's Average Total Inventories for the
three
months ended in Mar. 2026 was €12.6 Mil. Proto Labs's Cost of Goods Sold for the
three
months ended in Mar. 2026 was €65.5 Mil.
Hence, Proto Labs's Days Inventory for the
three
months ended in Mar. 2026 was 17.52.
The historical rank and industry rank for Proto Labs's Days Inventory or its related term are showing as below:
WBO:PRLB'
s Days Inventory Range Over the Past 10 Years
Min: 16.47 Med: 17.64 Max: 26.56
Current: 16.9
During the past 13 years, Proto Labs's highest Days Inventory was 26.56. The lowest was 16.47. And the median was 17.64.
WBO:PRLB's Days Inventory is ranked better than 97.34% of 2969
companies
in the Industrial Products industry
Industry Median: 119.47
vs WBO:PRLB: 16.90
Proto Labs's Days Inventory
increased
from Mar. 2025 (16.76) to Mar. 2026 (17.52).
It might indicate that Proto Labs's sales slowed down.
Inventory Turnover measures how fast the company turns over its inventory within a year.
Proto Labs's Inventory Turnover for the
three
months ended in Mar. 2026 was 5.21.
Inventory-to-Revenue determines the ability of a company to manage their inventory levels. It measures the percentage of Inventories the company currently has on hand to support the current amount of Revenue.
Proto Labs's Inventory-to-Revenue for the
three
months ended in Mar. 2026 was 0.10.
Proto Labs (WBO:PRLB) Days Inventory Explanation
Days Inventory indicates the liquidity of the inventory. Generally, a lower Days Inventory is preferred as it indicates a shorter duration to clear off the inventory. An increase of the ratio may indicate the company's sales slowed. Similar ratios related to Days Inventory are:
1. Inventory Turnover measures how fast the company turns over its inventory within a year.
Proto Labs's Inventory Turnover for the
three
months ended in Mar. 2026 is calculated as
2. Inventory-to-Revenue determines the ability of a company to manage their inventory levels. It measures the percentage of Inventories the company currently has on hand to support the current amount of Revenue.
Proto Labs's Inventory to Revenue for the
three
months ended in Mar. 2026 is calculated as
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
Be Aware
A lot of business are seasonable. It makes more sense to compare Days Inventory from the same period in the previous year instead of from the previous quarter.
Proto Labs Days Inventory Related Terms
Proto Labs Days Inventory Historical Data
* Premium members only.
The historical data trend for Proto Labs's Days Inventory can be seen below:
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
WBO:PRLB vs RYZ, WOR, MEC: Days Inventory Comparison
For the Metal Fabrication subindustry, Proto Labs's Days Inventory, along with its competitors' market caps and Days Inventory data, can be viewed below:
* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.
Proto Labs Days Inventory vs Industrial Products Industry
For the Industrial Products industry and Industrials sector, Proto Labs's Days Inventory distribution charts can be found below:
* The bar in red indicates where Proto Labs's Days Inventory falls into.
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
Proto Labs (WBO:PRLB) has a Days Inventory of 17.52 as of Mar. 2026. Days inventory represents the average amount of days a company holds inventory before selling it. View historical data on Proto Labs and its competitors. This is near median its historical median of 17.64. Over the past decade, Proto Labs' Days Inventory has ranged from 16.47 to 26.56. According to the industry distribution chart, Proto Labs ranks #79 out of 2969 companies in the Industrial Products industry, placing it in the top 2.7%.
Is Proto Labs' Days Inventory too high?
Proto Labs' current Days Inventory of 17.52 is near median its 10-year median of 17.64. Over the past 10 years, this metric has ranged from a low of 16.47 to a high of 26.56. The Industrial Products industry median Days Inventory is 119.47. Proto Labs' value of 17.52 is 85.3% below this industry median. Based on the distribution chart, Proto Labs ranks #79 out of 2969 companies in the Industrial Products industry, which is in the top quartile — a strong position relative to peers. Overall, Proto Labs has a GF Score™ of 66/100 and is considered Significantly Overvalued, reflecting its overall financial health beyond just this single metric.
How does Proto Labs' Days Inventory compare to RYZ and WOR?
According to the Industrial Products industry distribution chart, Proto Labs ranks #79 out of 2969 companies for Days Inventory. This places Proto Labs in the top 3% of its industry — outperforming the majority of peers. The industry median Days Inventory is 119.47. Proto Labs' value of 17.52 is 85.3% below this benchmark. Historically, Proto Labs' own Days Inventory has ranged from 16.47 to 26.56 over the past decade. While the company's 10-year median is 17.64 vs. the industry median of 119.47, Proto Labs has consistently been below the industry average. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Days Inventory for an Industrial Products company?
The median Days Inventory among Industrial Products companies is 119.47, based on 2,969 companies in the industry. Companies in the top quartile (top 25%) have a Days Inventory significantly above this median, while those in the bottom quartile fall well below. However, Days Inventory should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Proto Labs's current Days Inventory of 17.52 is 85.3% below the industry median. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Days Inventory mean?
A high Days Inventory can signal that a stock is expensive relative to its fundamentals. Days inventory represents the average amount of days a company holds inventory before selling it. View historical data on Proto Labs and its competitors. For the Industrial Products industry, the median Days Inventory is 119.47 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Proto Labs's current Days Inventory is 17.52, which is near median its own 10-year median of 17.64. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Proto Labs stock overvalued right now?
Based on GuruFocus' analysis, Proto Labs (WBO:PRLB) is currently considered Significantly Overvalued. The stock's GF Value™ is €37.76, compared to a current price of €65.65 — trading 73.9% above its estimated fair value. The current Days Inventory is 17.52, which is near median its 10-year median of 17.64 and 85.3% below the Industrial Products industry median of 119.47. Proto Labs' overall GF Score™ is 66/100 with 7 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Days Inventory calculated?
Days Inventory is calculated from a company's financial statements. For Proto Labs (WBO:PRLB), the current Days Inventory is 17.52 as of Mar. 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.
Is Proto Labs (WBO:PRLB) Overvalued in 2026?
Based on GuruFocus' analysis, Proto Labs stock appears to be overvalued.
The current stock price of €65.65 is trading 73.9% above its estimated GF Value™ of €37.76.
GuruFocus considers Proto Labs to be Significantly Overvalued.
Key valuation signals for WBO:PRLB:
Days Inventory: 17.52 (near median its 10-year median of 17.64)
GF Value™: €37.76 vs. price of €65.65 (73.9% above fair value)
Industry Position: 85.3% below the Industrial Products median (#79 of 2969)
No single metric tells the full story. See the WBO:PRLB stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Proto Labs Inc is an on-demand manufacturer of custom parts for prototyping and short-run production. The company offers developers and engineers quick-turn production services to reduce the time to market. The Lab uses injection molding, computer numerical control machining, and 3-D printing, and sheet metal to manufacture custom parts for its clients. The company services clients' needs for prototype solutions, parts for testing procedures, bridge production capabilities during disruptions in manufacturing processes, limited-quantity requests, and end-of-life production support. Geographically, a majority of the company's revenue is derived from the United States and the rest from Europe.
66GF Score
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