USB-C charging can be shrouded in mystery, especially when you have an unfamiliar cable or power adapter, or you have one of those multi-port chargers that has all sorts of arbitrary rules for how it splits power between plugged-in devices. That's why I wrote this little menu bar utility that displays how much power your computer (thinks it) is charging with. I designed this app to be simple and unobtrusive, and light on system resources--it only updates when it detects a change in charging status.
Note: This app can only report what the system is requesting from the charger, which may not necessarily reflect actual values. Think of it as displaying your computer's charging "mode" rather than actually measuring power directly.
This app is compatible with Intel and Apple Silicon portable Macs running macOS 10.13 "High Sierra" or newer. Although intended for Macs that charge via USB-C/MagSafe 3, this app also partially supports older MagSafe 1 and 2 Macs (though you might not see current/voltage information)
Hop on over to the Releases to grab your copy of WhatWatt! I'm not enrolled in the Apple Developer Program, so your computer might not trust me. If it refuses to open the app, just right-click and select "Open" from the menu.