Her level of super strength (as granted to her by Demeter) is comparable to that of the Earth itself (as this is where she derives her powers). She is on the same strength level with the strongest other DC’s characters including Superman and Captain Marvel. Thus, she is capable of lifting/carrying thousands of tons with minimal effort. It is generally accepted that she is a notch below Superman. Wonder Woman was even able to take on Powergirl in a hand to hand fight while trying to free her from mind-control. Wonder Woman and Captain Marvel were an even match when they fought. On one occasion she even used her massive strength to move the Earth (though this was under duress and aided by Superman and the Martian Manhunter.) With the launch of the new 52 Wonder Woman showed a new strength level while fighting a God, she removes her bracelets and goes into a "berzerker rage" of power, which originally allegorical to a person losing control to their destructive Ego. We then find out that Wonder Woman's bracelets are what protects her opponents from her intense power. Wonder Woman had a quick match with Supergirl where we found out that they are close in strength, Wonder Woman over powered Supergirl with her bracelets still on.
Following the Rebirth retcon, the "Year One" storyline explains that while put in a cell after coming to Man's World, Diana was visited by the Greek gods in animal form. Each gave her powers that would reveal themselves when she needed them to. She first displays strength when she accidentally rips the bars off her cell door when visited by Steve Trevor, Etta Candy, and Barbara Ann Minerva. Later on a trip to the mall, she discovers super speed, great durability, and the power of flight while fighting off a terrorist attack.
^ Mozzocco, J. Caleb. "The Many Loves of Wonder Woman: A Brief History Of The Amazing Amazon's Love Life". ComicsAlliance. Archived from the original on August 30, 2012. Retrieved August 28, 2012. When the next volume of Wonder Woman would start, Trevor was sidelined as Diana's love interest. He still appeared in the series, but as an older man, one who would ultimately marry the post-Crisis version of Wondy's Golden Age sidekick, Etta Candy.
^ Greenberger p. 175: "Journalist and feminist Gloria Steinem...was tapped in 1970 to write the introduction to Wonder Woman, a hardcover collection of older stories. Steinem later went on to edit Ms. Magazine, with the first issue published in 1972, featuring the Amazon Princess on its cover. In both publications, the heroine's powerless condition during the 1970s was pilloried. A feminist backlash began to grow, demanding that Wonder Woman regain the powers and costume that put her on a par with the Man of Steel."