How Long It Takes Tadpoles to Turn Into Frogs: (90 Species)

Many people know that most frogs lay eggs, which then hatch into tadpoles that develop and metamorph into adult frogs over time. But how long does it take for tadpoles to turn into frogs?

In general, most tadpoles take anywhere from 6 weeks to as long as 8 months to turn into frogs depending on the species, availability of food, and environmental conditions. However, the tadpoles of some species, such as the Coastal-tailed frog can take up to 4 years to turn into frogs. 

Tadpoles will typically develop faster in warmer temperatures, and slower in colder temperatures.

Other factors that affect tadpole development rate include the availability of food, and how crowded the pool is, among other factors.

Tadpoles in crowded pools will take longer to turn into frogs than those in less crowded pools (more information on that is below).

How Long the Tadpoles of 90 Frog Species Take To Turn Into Frogs

There are over 6,000 species of frogs around the world, found on every continent, except Antarctica.

Most of these frogs reproduce by laying eggs, which hatch into tadpoles that transform into adult frogs over time.

How long the tadpoles of a particular frog species take to turn into frogs can vary dramatically between species.

The tadpoles of some spadefoot toads can turn into frogs (toads) in as little as 2 weeks, while the tadpoles of the Coastal-tailed frog can take up to 4 years before they transform into frogs.

Below is a table that shows approximately how long the tadpoles of 30 frog species take to turn into frogs:

Frog Species
Scientific Name
How Long Their Tadpoles Take to Turn Into Frogs 
Wood frog Lithobates sylvaticus 65 – 130 days
Pickerel Frog Lithobates palustris 60 – 90 days
Northern Leopard Frog Lithobates pipiens 60 – 80 days
American bullfrog Lithobates catesbeianus 1 – 3 years
Green frog Rana clamitans 3 months – 1 year
Bronze frog Lithobates clamitans clamitans 3 months – 2 years
African bullfrog Pyxicephalus adspersus 17 – 35 days
Pacman frog Ceratophrys 3 weeks – 2 months
Mink frog Lithobates septentrionalis 1 – 2 years
River frog Rana heckscheri 1 – 2 years
Crawfish frog Lithobates areolatus 65 – 95 days
Pig Frog Rana grylio 1 – 2 years
Coastal tailed frog  Ascaphus truei 1 – 4 years
Carpenter frog Rana virgatipes 1 – 1.5 years
Gopher frog Lithobates capito 87 – 225 days
Northern red-legged frog Rana aurora 3 – 7 months
California red-legged frog Rana draytonii 4 months – 1 year
Foothill yellow-legged frog Rana boylii 3 – 4 months
Tarahumara frog Rana tarahumarae 1 – 2 years
Cascades frog Rana cascadae 2 – 3 months
Columbia spotted frog Rana luteiventris 2 – 7 months
Oregon spotted frog Rana pretiosa 3 – 4 months
European common frog Rana temporaria 2 – 4 months
Mexican white-lipped frog Leptodactylus fragilis 2 – 5 weeks
African clawed frog Xenopus laevis 1 – 3 months
African dwarf frog Hymenochirus 2 – 3 months
Tomato frog Dyscophus 2 – 3 months
Florida bog frog Lithobates okaloosae 1 – 1.5 years
Northern sheep frog Hypopachus variolosus 3 – 4 weeks
Marsh frog Pelophylax ridibundus 3 months – 1 year

How Long Tree Frog Tadpoles Take To Turn Into Frogs

Below is a table that shows approximately how long the tadpoles of 30 tree frog species take to turn into frogs:

Frog Species
Scientific Name
How Long Their Tadpoles Take to Turn Into Frogs (Approx.)
Gray tree frog Hyla versicolor 45 – 65 days
Cope’s gray tree frog Hyla chrysoscelis 45 – 65 days
Spring peeper Pseudacris crucifer 45 – 90 days
American green tree frog Hyla cinerea 24 – 45 days
Cuban tree frog Osteopilus septentrionalis 30 – 60 days
Pacific tree frog Pseudacris regilla 2 – 3 months
Poison dart frogs Dendrobatidae 2 – 3 months
Glass frog Centrolenidae 4 months – 1 year
Red-eyed tree frog Agalychnis callidryas 2 – 3 months
Amazon milk frog Trachycephalus resinifictrix 1 – 2.5 months
Spotted chorus frog Pseudacris clarkii  1 – 2 months
Pine woods tree frog Hyla femoralis 2 – 3 months
Barking tree frog Hyla gratiosa 2 – 5 months
Squirrel tree frog Hyla squirella 1 – 2 months
Australian green tree frog Litoria caerulea 1 – 2 months
European tree frog Hyla arborea 2 – 3 months
Blanchard’s cricket frog Acris blanchardi 2 – 3 months
Southern cricket Frog Acris gryllus 3 -4 months
Northern cricket frog Acris crepitans 1 – 3 months
Pine Barrens tree frog Dryophytes andersonii 2 – 2.5 months
Canyon tree frog Hyla arenicolor 1 – 2 months
Boreal chorus frog Pseudacris maculata 2 – 3 months
Bird-voiced tree frog Hyla avivoca 3 – 4 weeks
Arizona tree frog Hyla wrightorum 2 – 3 months
Little grass frog Pseudacris ocularis 2 – 2.5 months
Coronated tree frog Anotheca spinosa 2 – 4.5 months
New Jersey chorus frog Pseudacris kalmi 1 – 2 months
Mediterranean tree frog Hyla meridionalis 2 – 3 months
Italian tree frog Hyla intermedia 2 – 3 months
Iberian tree frog Hyla molleri 2 – 3 months

How Long Toad Tadpoles Take To Turn Into Toads

Below is a table that shows approximately how long the tadpoles of 30 toad species take to turn into toads:

Toad Species
Scientific Name
How Long Their Tadpoles Take to Turn Into Frogs (Approx.)
American toad Anaxyrus americanus 1 .5 – 2.5 months
Fowler’s toad Anaxyrus fowleri 1 .5 – 2 months
Western toad Anaxyrus boreas 1 – 1.5 months
Cane toad Rhinella marina 3 weeks –  6 months
Great Plains toad Anaxyrus cognatus 1.5 – 2 months
Canadian toad Anaxyrus hemiophrys 1.5 – 2 months
European toad Bufo bufo 2 – 3 months
Natterjack toad Epidalea calamita 1.5 – 2 months
Arizona toad Anaxyrus microscaphus 2 – 3 months
Southern toad Anaxyrus terrestris 1 – 2 months
Colorado River toad Incilius alvarius 3 – 4 weeks
African common toad Sclerophrys regularis 2 – 5 months
Mexican burrowing toad Rhinophrynus dorsalis 1 – 3 months
Oriental fire-bellied toad Bombina orientalis 2 – 5 months
Wyoming toad Anaxyrus baxteri 1 – 2 months
Eastern spadefoot toad Scaphiopus holbrookii 1 – 2 months
Western spadefoot toad Spea hammondii 1 – 2.5 months
North American green toad Anaxyrus debilis 2 – 4 weeks
Red-spotted toad Anaxyrus punctatus 1.5 – 2 months
Houston toad Anaxyrus houstonensis 2 weeks – 3 months
Eastern narrow-mouthed toad Gastrophryne carolinensis 3 weeks – 2.5 months
Yosemite toad Anaxyrus canorus 1 – 2 months
Woodhouse’s toad Anaxyrus woodhousii 1 – 2 months
Oak toad Anaxyrus quercicus 1.5 – 2 months
Arroyo toad Anaxyrus californicus 2 – 3 months
Sonoran green toad Anaxyrus retiformis 2 – 3 wees
Great Plains narrow-mouthed toad Gastrophryne olivacea 1 – 2 months
Coastal plains toad Incilius nebulifer 3 – 4 weeks
Great Basin Spadefoot Spea intermontana 1 – 2 months
New Mexico spadefoot toad Spea multiplicata 2 weeks – 1.5 months

Stages of Development: From Tadpole to a Frog

1. Hatchling Tadpole

The first few days after hatching, tadpoles won’t have the energy to swim yet. They will feed on the remaining yolk of the eggs. This will provide them with enough energy to grow and develop further.

2. Swimming Tadpole

After a few days, the tadpoles are strong enough to swim around and will start feeding on food sources available in the water.

At this early stage, tadpoles have long coiled intestines that are specially designed to digest plant matter. They will only eat algae, plankton, and the soft roots of aquatic plants such as duckweed.

3. Toothed Tadpole

After about 4 – 6 weeks (can vary depending on species), the tadpoles grow teeth, and their intestinal tract will gradually shorten, allowing the tadpoles to eat animal matter.

Apart from plant matter, they also start to eat animal matter, such as small insects that fall into the water.

4. Tadpole With Legs

At about 6 weeks old, the tadpoles will start to grow legs, starting with the back legs. At this point, their gills are also covered by a special pocket of skin called an ‘operculum’ and become internal gills.

5. Froglet Stage

At 12 – 14 weeks old, the tadpoles have developed fully developed legs, and their lungs are getting larger. After their legs have developed, they become stronger and more refined.

Tadpoles at this stage look like tiny frogs with tails and will spend a lot of their time by the edge of the water, sometimes leaving the water.

A froglet with well developed legs, and a tail
A froglet with well-developed legs, and a tail.

Froglets cannot survive out of water for a long time, so they will return to their pond frequently at this stage.

6. Young Frog

At about 14 – 16 weeks, the tail is lost, and the legs are more refined. Once metamorphosis fully is complete, the tadpoles are now young frogs.

These frogs will leave the water, for life a land.

It is important to note that the time frames given here are rough generalizations and are not set in stone. Tadpole development rate varies, sometimes dramatically, between species. Also, many factors can make a tadpole grow faster or slower than is normal for that species (more information on that is below).

Temperature Affects How Long Tadpole Development Takes

Tadpoles that hatch in early spring, when the weather is colder, usually take longer to develop – and those that hatch later when the weather is warmer will typically develop faster.

This is because temperature affects development rates.

In general, tadpoles and other amphibian larvae will develop faster in warmer temperatures and slower in colder temperatures.

A tadpole of the Southern brown tree frog
Southern brown tree frog tadpole. Photo by: JJ Harrison jjharrison (CC BY-SA 3.0), via Wikimedia Commons.

Amphibians are ectothermic (cold-blooded) which means their body temperature varies with surrounding environmental temperature. As the temperature changes, so does their metabolism.

For tadpoles to develop normally and metamorph into froglets, the surrounding water temperature should stay within a certain range.

If the temperatures fall beyond their preferred range, their metabolism and development rate will decrease – and if the temperatures drop too low, tadpoles can completely stop developing.

To increase their body temperature above that of the surrounding water, tadpoles often huddle together. Doing this creates a greater surface area and increases the intensity of heat absorbed from the sun.

On the opposite end, if the temperatures rise above the preferred range, the tadpoles can have trouble getting enough oxygen from the water which can lead to a very high mortality rate.

This is because metabolism and tadpole activity increase with temperature, but at the same time, the amount of dissolved oxygen decreases with temperature.

In addition, in warmer temperatures, tadpoles will divert more of their energy towards maintaining adequate oxygen levels, rather than development. This can lead to a decreased rate of development.

Sometimes, Tadpoles Can Deliberately Delay Their Development Due to Cold Weather

Many frogs have extended breeding seasons, and some tadpoles hatch from their eggs late in the year.

When this happens, the tadpoles may choose to overwinter in the pond and finish their development the following spring.

Adult frogs hibernate during the winter. Their metabolism slows down, and they stop eating; instead using up energy reserves they created throughout the year.

However, newly metamorphosed frogs wouldn’t survive the winter as they have not gotten themselves ready for hibernation yet. So, some tadpoles may choose to put off metamorphosis until the following spring.

American bullfrog tadpole
Tadpoles of the American bullfrog commonly overwinter at the bottom of ponds. Photo by: Jacob McGinnis (CC BY-NC 2.0).

They will continue to swim and feed during the winter, provided it is not too severe.

If water temperatures near the surface of the pond get too low, the tadpoles can swim to deeper water where the water is warmer.

In this way, the tadpoles of some species, such as the American bullfrog can delay metamorphosis by up to 2 years – overwintering twice at the bottom of ponds.

There are advantages to delaying metamorphosis:

  • Tadpoles that wait a long time before becoming frogs can grow bigger by the time they change. Their larger size makes them well-equipped to find food and defend themselves.
  • Tadpoles that live through winter can become frogs early in the following spring. This gives them a head start over that season’s tadpoles in competing for resources.
  • Tadpoles may have a better chance of surviving the winter than adult frogs. This is because they are better suited at surviving low oxygen conditions, which is helpful as pond surfaces can freeze during winter.

When a pond freezes over, the layer of ice blocks air from the water’s surface, and there are no currents to mix oxygen into the water. Tadpoles have a higher surface area to volume ratio and can breathe through their skin more efficiently than most adult frogs.

Although overwintering frogs require less oxygen than they normally do, low oxygen conditions can still be fatal to them.

Since frozen ponds have lower oxygen levels, many frogs overwintering in frozen ponds do not survive the winter. This is known as “winterkill.”

Other Factors That Affect Tadpole Development Rate

1. Species

The tadpoles of some frog species grow and develop faster than others. For example, frogs that breed in temporal pools (such as spadefoot toads) that dry up in the summer, will have higher growth rates. This allows them to escape their ponds before the water dries up.

However, frogs that breed in permanent ponds (such as the American bullfrog) are in no rush to leave the water and can afford to develop at much slower rates.

2. Food Availability

Diet is an important factor that influences tadpoles’ development, and ultimately metamorphosis.

In a lab experiment, tadpoles raised on a high-quality diet grew faster and transformed into frogs quicker than tadpoles raised on a low-quality diet.

In another experiment, tadpoles starved early in development delayed metamorphosis by 8%, and those starved midway in their development took 19% longer to undergo metamorphosis.

3. Crowding

When tadpoles are in crowded pools, they develop slower and will take longer to go through metamorphosis. Tadpoles in crowded pools have been found to develop slower even with a high availability of food.

In one experiment, a researcher raised tadpoles in different volumes of water. He found that crowding has little effect on the rate of tadpole development during the first 2 weeks. But later development greatly affected – decreasing rapidly in crowded conditions.

It was also found that the tadpoles that grew to the greatest body size went through metamorphosis earlier than tadpoles that remained small.

In addition, another experiment found that tadpoles developed slower when raised in water previously crowded by other larger tadpoles.

Sometimes, large tadpoles in crowded pools eat smaller, more vulnerable tadpoles. Doing this not only gives them nutrients but also eliminates competition for resources.

4. Environmental Cues

Tadpole development rate can be influenced by various environmental cues. For instance, tadpoles in drying pools have been found to respond by metamorphosing more quickly.

However, the newly metamorphosed frogs will be smaller than those from slower-drying pools.

Some Tadpoles Can Morph and Develop Faster

Some tadpoles, such as those of spadefoot toads are polymorphic: meaning they can develop in more than one form.

Normally, spadefoot tadpoles are omnivores that have jaw muscles and mouthparts that are proportioned when compared to the rest of the body. These are called ‘omnivore morphs.’

plains spadefoot toad tadpoles
Plains spadefoot toad tadpoles. Photo by: Charles (Chuck) Peterson (CC BY-NC-ND 2.0).

However, the tadpoles can also develop into ‘carnivore-morph’ tadpoles, that eat fairy shrimp and other prey. They can also become cannibalistic and eat other tadpoles.

Despite being the same age as ‘normal’ spadefoot toad tadpoles, carnivore-morph tadpoles are larger, and have bigger, broader heads, a slimmer body, and smaller guts.

They also have keratinized mouthparts that are bigger and have serrated edges, with a dorsal hook.

These two morphs behave differently: omnivore-morph tadpoles gather in schools, while carnivore-morph tadpoles are solitary.

Canivore-morph spadefoot tadpoles tend to develop more quickly than their ‘normal’ counterparts, due to their high-protein diet.

Most Tadpoles Never Get To Turn Into Frogs

The tadpole stage is the most vulnerable stage of most frogs’ and toads’ lives. Frogs often lay eggs in temporary pools of water, and sometimes, these pools dry up before the tadpoles have had enough time to metamorph into adults.

In addition, tadpoles are also preyed on by fish, adult frogs and toads, salamanders, newts, birds, snakes and other reptiles, many mammals, and even predatory insects such as water boatmen and dragonfly larvae.

For these reasons, it’s common for over 90% of tadpoles in a pond to be wiped out before they can undergo metamorphosis and transform into adult frogs.

Frequently Asked Questions:

When Do Tadpoles Leave the Water?

Tadpoles leave the water when they reach the froglet stage, which is about 12 – 16 weeks in many species. At this point, the tadpole’s gills have disappeared, its lungs have grown larger, and its limbs have completely developed.

Newly transformed froglets look like tiny frogs with tadpoles tails. A few weeks later, the tail is lost and metamorphosis is complete.

How Can You Tell How Old a Tadpole Is?

The best way to guess how old a tadpole is – is by looking at its stage of development. Generally, If a tadpole is not yet swimming or eating, it’s at least less than 4 days old. If a tadpole has full gills, and no legs, it’s most likely less than 4 weeks old.

If a tadpole has teeth and is omnivorous (can eat animal matter), it is at least 6 weeks old – and If a tadpole has well-developed legs, and looks like a tiny frog with a tail, it is at least 12 weeks old.

It’s important to note that these figures are rough estimations and are not set in stone. The tadpole development rate can vary between species. Also, there are many factors that make a tadpole grow faster or slower than is normal for that species (mentioned above).

How Long Does It Take for Tadpoles to Hatch?

Tadpoles can take anywhere from 12 hours to as long as 6 weeks to hatch depending on the species, and environmental temperature. Tadpoles will develop and hatch faster at warmer temperatures, and slower are colder temperatures.

What Month Do Tadpoles Turn Into Frogs?

In the Northern Hemisphere, the tadpoles of most frogs that lay eggs in early spring will start turning into frogs by late April to early May. However, some tadpoles can turn into frogs by June or July, or even as late as September.

Photo credit: the1pony (CC BY-ND 2.0).