The WTA promises that prize money will be the same at combined events by 2027 and at non-combined events by 2033.
The amount of WTA 1,000 tournaments, which are the highest level of competition outside of the Grand Slams, will go up from 8 to 10.
By 2025, seven of the ten events will last for two weeks.
It will also try to get equal prize money for WTA 1,000s and 500s that aren’t part of a joint tournament by 2033.
The WTA says the change will make sure that “the best athletes are always at these top events.”
Sloane Stephens, a former US Open champion, said, “Every generation works to leave their sport in a better place for the next.”
“I’m proud to be a part of this change, and I fully back the WTA’s efforts to move forward.”
Equal prize money was one of the main goals of the players who started the WTA 50 years ago.
Carlos Alcaraz and Elena Rybakina both won the singles titles at the recent Indian Wells 1,000 event and took home $1,262,220 (£991,902.96) each.
But at the Italian Open, Daniil Medvedev won the singles title and got £1,105,265 (£950,000). Rybakina, who won the women’s title, got £521,754 (£449,060).
The Italian Open has also said that the prize money will be the same by 2025.
The draws for the current WTA 1,000 events in Rome, Beijing, Cincinnati, and Toronto will be stretched out over two weeks.
There will also be one-week events in Doha, Dubai, and a place that hasn’t been named yet.
There will be 17 more WTA 500 events, and the WTA 250s will have a “stronger regional focus” to help the next crop of tennis players.