Harry Styles' 'Love On Tour' concert series raised $6.5 million for charity.

The 'Watermelon Sugar' hitmaker played the 173rd and final date of his near-three year live run at Italy's RCF Arena last week, and newly-released data shows he performed to 5.04 million fans in North and South America, Australia, the UK and Europe and is the fourth highest-grossing tour of all time.

Charities who benefitted from the tour included Planned Parenthood, Physicians for Reproductive Health, Choose love, Black Voters Matter Fund — Capacity Building Institute, International Rescue Committee, Every Town for Gun Safety, Black Minds, REVERB, Intermission Youth, Save the Children, CARE, and The Afiya Center.

In addition, Harry helped register more than 54,000 voters after teaming up with non-profit organisation HeadCount to boost voter turnout by offering fans the chance to attend his costumed celebration Harryween in Los Angeles last October.

Two days after Harry's final show on 22 July, the former One Direction singer hailed the tour the "greatest experience of [his] life".

He wrote: "Love on Tour. It's been the greatest experience of my life.

"Thank you to my band, all the crew who made the last few years so special. It's been an absolute pleasure.

"To everyone who came out to see us play, thank you.

"I feel so incredibly full and happy, it's all because of you. You have given me memories that will last a lifetime, more than I could have ever dreamed of.

"Thank you for your time, your energy, and your love. It's been an honour to play for you. I hope you had as much fun as I did."

And the 29-year-old singer promised he'll be back on stage "when the time is right".

He wrote: "Look after each other, I'll see you again when the time is right. Treat People With Kindness. I love you more than you'll ever know."