Funnily enough, the pair worked together on Hoult's breakout movie About a Boy over 20 years ago, a fabulous comedy-drama charting the unlikely friendship between rich rogue Will Freeman and impoverished school kid Marcus Brewer.
"I think that was maybe a formative experience – I'm guessing, I don't know," McKay told NME.
"I'm just assuming because, you know, [Nick was] around somebody like Grant at a really young age and watching him perform at a high level. I think there's something about Hugh Grant's early charm that is similar to what Nick does."
Elsewhere, while promoting his new bloodsucking comedy Renfield on the BBC Radio 1 breakfast show this week, Hoult decided to dial up legendary co-star Nicolas Cage during a game designed by presenter Greg James.
"It's so early in the morning," said the Dracula actor after answering, leading Hoult to apologise profusely.
This only made Cage chuckle down the line, as he insisted: "That's alright, I was up anyway. I was just surfing some net… I was looking at old Studebakers, the old classic American car. I love the shape."
A casual conversation about whether or not Cage might purchase one then ensued, with Hoult also sharing his love for Cage's action heist flick Gone in 60 Seconds, which came out in 2000.
“I am looking forward to doing something with you again Nick," Cage admitted.
"I had a blast working with you on this."
Renfield is out now in cinemas.
Watch: Renfield's Nicolas Cage and Nicholas Hoult on prosthetics and sequels