Katy Perry. Photo by Jordan Strauss/Invision/AP

Katy Perry has been named Forbes magazine's highest paid woman in music in 2018, beating the likes of Taylor Swift and Rihanna to the title.

The 'Roar' hitmaker has topped the business publication's annual list with earnings of $83 million before tax over the 12 months from June to June, with the 80 dates of her huge 'Witness' world tour contributing the bulk of the cash receipts.

Meanwhile, Katy's role on the judging panel for 'American Idol' reportedly netted her a further $20 million.

The numbers are calculated using "pre-tax earnings from 1 June 2017, through 1 June 2018, before deducting fees for agents, managers, lawyers and estate executors".

Following Katy in second place on the list is Taylor Swift who banked $80 million over the year thanks to her hit album 'Reputation'.

The LP sold two million copies in its opening weekend, and the 'Blank Space' hitmaker was also helped by her subsequent stadium tour in support of the LP.

Forbes suggested that Taylor could have landed in the top spot if more of her live dates had fallen within the 12 month period.

There's a chance Taylor could find herself further up the rankings for 2019 too, after it was revealed this week she has signed a new global recording agreement with Universal Music Group.

She spent her career to date signed to independent label Big Machine, meaning this move is her first major label deal.

Rounding off the top five after Katy and Taylor are Beyonce ($60 million), Pink ($52 million) and Lady Gaga $50 million), with Jennifer Lopez ($47 million) just missing out in sixth place.

They're followed by Rihanna ($37.5 million), Helene Fischer ($32 million), Celine Dion ($31 million) and Britney Spears ($30 million).

Forbes' highest paid women in music in 2018 top 10:

1. Katy Perry ($83 million)

2. Taylor Swift ($80 million)

3. Beyoncé ($60 million)

4. Pink ($52 million)

5. Lady Gaga ($50 million)

6. Jennifer Lopez ($47 million)

7. Rihanna ($37.5 million)

8. Helene Fischer ($32 million)

9. Celine Dion ($31 million)

10. Britney Spears ($30 million)