The new CEO of one of Australia's largest banks failed an accounting subject twice because he's "more comfortable with people than with figures".

Ross McEwan was officially named as the new head of National Australia Bank (NAB) last week and is set to replace embattled former boss Andrew Thorburn.

McEwan will begin the role in April 2020 at the latest and will be paid a "fixed remuneration of A$2.5 million ($2.6m)" per year.

However, his actual salary will likely be far higher, with the "potential to earn between 0 per cent and 150 per cent of fixed remuneration" — which could mean an extra A$3.75m — and "an annual grant of up to 130 per cent of fixed remuneration", which would be a potential A$3.25m bonus.

That would bring his earnings up to A$9.5m, with possible dividends from his vesting rights likely to push that figure even higher.

But while McEwan has enjoyed a glittering banking career, it turns out numbers are not exactly his forte.

The father of two, who was most recently the boss of the Royal Bank of Scotland, failed a key accounting subject at university — not once, but twice.

McEwan, who was born in Hastings, New Zealand, eventually graduated with a Bachelor of Business Studies from Massey University.

But in a November 2000 interview with alumni magazine Massey, McEwan, who was then "one of New Zealand's youngest chief executives" at insurance firm AXA, revealed his career got off to a rocky start.

He told the university he looked back at his time at the university with "fondness and regret" as he only managed to pass the critical Accounting Level 2 course on his "third attempt".

"Since attending Massey in the late '70s many things have changed. Gone are the days of cramming study into the last eight weeks of the varsity year, long hours in the cafeteria and not the library … weekdays spent at the Massey gym — and a degree made up of C passes," he said.

"I got there in the end though and was part of the first group of students in New Zealand to graduate with a business studies degree majoring in human resources.

"But if you check my academic records you'll see I failed Accounting Level 2 twice before getting it on the third attempt."

Even more surprising was McEwan's explanation for his academic failure — especially considering his chosen career.

"I'm more comfortable with people than with figures. No regrets there," he said.

"It wasn't a priority for me then. Now I'm in this role, it would have been nice, very nice, to have put more time into it."

McEwan graduated in 1979 and went on to marry fellow Massey graduate Stephanie Duncan. The pair have two adult daughters.

He previously worked for the Commonwealth Bank as its group executive of retail banking — but was snubbed when the bank's open CEO role was given to Ian Narev instead.

McEwan moved on to the Royal Bank of Scotland Group where he worked as CEO UK Retail from 2012-2013 before taking over as chief executive.

He joins NAB following the resignation of former CEO Andrew Thorburn in February this year after he was shamed in banking royal commissioner Kenneth Hayne's scathing final report.

Thorburn pocketed a lucrative golden handshake of more than $1 million on his way out the door.