Converts imperial units to metric on McMaster-Carr and toggles tooltips via toolbar button.
Users
110
+9 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
5
0 in 30 days
Store rank
#82K
#68K among extensions
Version
1.1.1
updated 23 May 2026
Users
monthly, 17 months
Latest, 18 Oct 2026:110 usersMove the mouse over the chart for any month
Ratings count
monthly, 17 months
Latest, 18 Oct 2026:5 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About Metric McMaster
Metric McMaster automatically converts imperial units to metric as you browse McMaster-Carr product pages. Unlike general converter extensions, Metric McMaster is designed around the formatting and measurement styles used on the McMaster website, helping provide accurate conversions where generic tools may miss values.
When you visit mcmaster.com, the extension detects imperial measurements and displays their metric equivalents in tooltips. Hover over a converted value to see its metric conversion, or toggle persistent conversion tooltips with the extension toolbar button or Alt+X. Tooltip rows can also be clicked to copy the raw metric number.
This extension is useful for engineers, students, and anyone who prefers metric units when sourcing parts, making it faster to read product specifications without manual calculations or switching tabs.