I can see the advertised max 180 OpenVPN / 900Mbps for WireGuard but it's "over ethernet"
What's the theoretical best speed over WiFi (assuming at close range)?
Just curious as over ethernet tells me very little of what it will be like as won't be using a wifi router over ethernet
Difficult (impossible) to tell because it depends on your devices.
The VPN speed via Wi-Fi could be the same or less. Mostly it will be less, but as I said before it depends on your devices, frequencies and stuff.
At least you can be sure that it won't be faster than ethernet 
Yes, you right.
My new mobile has WiFi 7. I tested wifi with flint 2 and VPN wireguard = nearly 800mbps.
All good with WiFi depend devices.
It's not impossible to tell because I'm not asking what speed will I get - I'm asking the maximum (under optimal conditions) that is possible
There is a limit in best case conditions that it can reach (that limit will be lower than ethernet)
The key thing I was trying to avoid is that it advertises max 900Mbps (wired wireguard) but if WiFi maxed out at half that speed I'd want to know so I can choose if it fits my needs
So I have 2Gbps line and have latest-gen devices like m4 macbook / iPhone 16 Pro - so should be able to get the upper range of what's possible.
Maximum speed using Wi-Fi will be the same or a bit slower than using Ethernet.
VPN doesn't care if it's used by wires or wireless...
I would say the same speed as WLAN. Again depends on device speed and ISP.
I have a question, why can't I reach the speed of 900mbps with wireguard with Nord Vpn, in the speed test on the wire I don't pass 650mbps.
If you can reach the speed without VPN but not with Nord, then try another VPN provider.
Mostly it will be an issue with Nord then.
without VPN I have 932 mbps download and 935 upload
PIA nearly 700-800mbps (wired and wireless)
Without VPN 900mbps (wired and wireless)
Can I ask - with Nord, are you using OpenVPN?
Log in to your router with ssh and check if your CPU cores are 100% loaded.
Yes - most likely router is the bottleneck.
No - probably your VPN provider is the culprit. Note that Wireguard, as any VPN, adds some overhead. This means you won’t be able to get full line speed.
