How long does it take

Tadpoles love lettuce. Boil it for 10 to 15 minutes and drain it. Chop it up a little and then you can lay it on a tray to freeze it. Give the tadpoles a pinch every few days. Too much food will make the water dirty, too little will make the tadpoles go nutty and try to eat each other. Frog development from tadpole to frog usually takes 6 - 12 weeks. Mostly the length of time a tadpole takes to develop depends on what type of frog the eggs are from. When the tadpoles start to develop legs they will need a perch so they can get out of the water. Floating water lily leaves and branches are ideal, but you can also create ledges using stones or even tilting slopes of plastic in tanks. Once they have legs you can start to feed them small insects and live bloodworms which you can buy at any pet store that carries fish. You can feed them to the frogs by taking the lid of a jar and turning it upside down. Fill the cap with a bit of warm water and add a bunch of worms and the frogs will find them. You can also add the worms directly to the water. Aphids are also a great food source. They can be found on certain types of dandelions, just snip off a stem and place it in the tank, your tadpoles will have a feast!

I would add to the other comments that I think development is also related to temperature. I have noticed that the frogspawn in our kitchen has developed much faster than the same frogspawn in the pond in the woods.

It varies from the type of frog, but it can take anywhere from three days to three weeks depending on the species, for the tadpole to emerge from the frogspawn with a tail. Then, about another five weeks before it develops legs and bulges appear where their front legs are growiTheir tails become shorter and they begin to develop lungs, in preparation for it's life on land, as a frog. From this point it becomes more and more froglike until some eleven weeks after its egg was laid a fully developed frog with lungs, legs, and no tail emerges from the water. Brightest Blessings.