16GB is the minimum for a 4GB VM on Windows or macOS

Yes, 16GB will help. With 8GB total, you’re already underwater before the VM boots.

The host OS itself needs 2–4GB just to sit there. Add a browser, Slack, whatever. That leaves maybe 4GB for the host. Your VM gets 4GB. Now both are fighting over the same physical RAM, and the OS starts swapping to disk. Swapping is slow. Your machine will stutter, your VM will lag, and you’ll hate life.

Move to 16GB and the math changes: host can use 8–10GB without breathing hard, VM gets its 4GB, and you still have a real buffer. No swapping. Everything feels snappy again.

If you’re running Linux as the host, you might squeeze by on 8GB with careful tuning. But on Windows or macOS? 16GB is where comfortable VM use starts.