Why does my toilet not flush good?

It could be the lift chain-Lift the top off the back of your toilet tank; if you have a lift chain, inspect it to see if there is too much slack or stretch. If there is, the flapper won’t rise and stay up long enough to let enough water into the toilet bowl to produce a full flush. Allow the flapper to stay up longer by removing the chain and rehooking it to a hole that is closer to the flush lever.

My did not flush good till I held the handle down till it flush all the way,no more problems.

Georgia

Also, a too-much-information tip here- do not flush anything except toilet paper! No wet wipes, no feminine products, etc. They catch on stuff and cause clogs.

Make sure the water level in the tank is high enough. It should be about 1" below the overflow tube. Adjust the float. Make sure there are only about three or four loose links on the flapper chain so the flapper seals. but will not be pulled down too soon on refill. The weight and friction of the flush handle pulls and holds the flapper up. The suction of the water refilling pulls the flapper gradually down. Too many loose links and it will close too soon preventing a full flush.

Some of the new stools are made to use less water and it DOES take more than one flush sometimes. William gave some good advise about the float and flapper mechanism.

I have the same issue and I've tried all those suggestions. Still doesn't work properly.

You need to get a toilet snake at Home Depot and snake it. I used to have one when I had my house - it was cheaper than calling a plumber. Can be messy, so lay old towels down and follow the directions. You've got a clogged pipe - if that doesn't do it, it could be that it needs to be done outside, of which at that point, I'd call a plumber. Sometimes tree roots can cause a problem. If you have children, you may have something stuck in the toilet where you can't see it, in that case, you'd have to remove the toilet to get it - there's videos on all this that you can Google. But the snake is the first thing I'd try. They're not expensive.