Britney Spears is earning $1 million a week.

The 'Toxic' hitmaker began a two-year residency at Planet Hollywood in Las Vegas in December 2013 and it has now emerged that ticket sales were so successful, after just 50 shows her representatives renegotiated her contract from $310,000 per performance to $475,000, including her share of merchandising and other perks.

The deal - which means Britney earns just $1,000 less than the city's biggest earner, Celine Dion - also saw the number of shows the 32-year-old star will perform over the duration of her residency rise from 92 to 140, TMZ reports.

The staggering pay cheque from her residency, plus income from record sales and other ventures mean the 'Piece of Me' hitmaker is banking around $1 million every week.

And it is just as well Britney - who has sons Preston, nine, and Jayden, eight, with ex-husband Kevin Federline - is earning so much as it was recently revealed she spends over $30,000 a year just on her dogs.

She forked out over $13,000 on a pair of pooches in 2013, a white Maltese in January and a Yorkie in July for $5,568 and $8,212 respectively as well as paying a staggering $5,205 to get her dogs looked after when she wasn't there.

The figures came courtesy of new legal documents filed in her conservatorship, which also revealed Britney spent a hefty $1,585 on clothes for her canines including $650 in one four-legged friend spending spree.

Her grand total spend of $31,234.15 on her pooches was completed by spends such as dog food.