Feeding guide
What size dubia roaches for a bearded dragon, and how many
Pick a dubia roach no longer than the gap between your bearded dragon's eyes. As a rough guide, that means Small (1/4 to 1/2 in) for hatchlings, Small then Medium for juveniles, and Medium to XL as the dragon reaches adult size. Feed hatchlings two to three small meals a day, juveniles daily, and adults insects three to four times a week.
The size rule and where it comes from
The common rule says a feeder insect should be no longer than the space between the dragon's eyes. The Association of Reptilian and Amphibian Veterinarians (ARAV) gives it in its bearded dragon care handout. The handout's main guideline is a prey body length no greater than 1/2 to 2/3 of the width of the dragon's head. It calls the eye gap a rule of thumb for the same limit.1
How well supported is it? It is veterinary advice, not a tested threshold. We found no study that fed dragons prey of different sizes and measured the outcome. The ARAV handout lists impaction among the most common disorders of bearded dragons, but it ties impaction to loose substrates such as sand and gravel, not to prey size.1 Treat the eye gap as a cautious habit. A roach that is slightly too small costs you nothing, so err on the small side.
Dubia are broader and flatter than crickets of the same length. If your dragon sits between two sizes, choose the smaller one.
How to measure
- Look at your dragon from above while it rests.
- Hold a ruler just over its head and read the distance between the inner edges of the eyes.
- Choose the dubia size whose range tops out at or under that number.
What size dubia roaches for a bearded dragon at each age
Ages below are rough. Dragons of the same age can differ a lot in size, so the eye gap decides. The feeding schedule comes from veterinary sources. The size column applies the eye-gap rule to our dubia roach sizes.
| Stage | Rough age | Eye gap | Dubia size | Insect meals |
|---|---|---|---|---|
| Hatchling | 0 to 3 months | Under 1/2 in | Small (1/4 to 1/2 in) | Two to three small meals a day1 |
| Juvenile | 3 to 12 months | About 1/2 to 3/4 in | Small, then Medium (1/2 to 3/4 in) | Once or twice a day1,2 |
| Subadult | 12 to 24 months | About 3/4 to 1 in | Medium, then Large (3/4 to 1 in) | Move from daily toward the adult schedule |
| Adult | Sexually mature, 1 to 2 years and up1 | 1 in or more | Large, or XL (1 in and up) for big adults | Three to four times a week1 |
Small dubia for hatchlings
ARAV describes baby dragons eating small meals two to three times a day, mostly small moving prey.1 The bottom of our Small dubia range starts at 1/4 in. Pick the smallest roaches from the box for a very young dragon.
Medium dubia for juveniles
Juveniles grow fast. ARAV says they need plenty of food offered daily, and VCA's veterinary authors say most young dragons eat once or twice a day.1,2 Expect to move from Small to Medium dubia during this stage, once the eye gap passes 1/2 in.
Large and XL dubia for adults
Adults need fewer insects. ARAV recommends live prey three to four times a week, making up about 25% of the day's food on those days, with salad and vegetables every day.1 VCA notes that adults may eat only every 24 to 72 hours because they are no longer growing.2 Adults with an eye gap of 3/4 to 1 in fit Large dubia. Save XL for big adults with an eye gap of 1 in or more.
How many dubia roaches to feed a bearded dragon
No study has set a dubia count per meal for bearded dragons. The veterinary sources give how often to feed and what share of the diet should be insects, not a number of roaches.1,2 The daily counts on many feeding charts online are keeper estimates, often written for crickets.
A method works better than a borrowed number:
- Offer correctly sized dubia one at a time, or a few in a smooth-sided dish the roaches cannot climb out of.
- Stop when your dragon loses interest. Many keepers cap a session at 10 to 15 minutes.
- Remove any uneaten roaches from the enclosure.
- Count what your dragon ate. Use that count as the starting point next time, then adjust as it grows.
Young dragons eat mostly insects. VCA says growing dragons tend to be insectivores and adults become more herbivorous.2 So expect the count per meal to rise through the juvenile months while the share of greens rises in adulthood.
Can dubia roaches make a bearded dragon overweight?
Yes, if you overfeed them, as with any feeder. The Merck Veterinary Manual says excess calories combined with limited exercise can quickly lead to severe obesity and fatty liver disease in captive reptiles. Treatment is more exercise and a slow cut in calories over many months.3
A 2025 veterinary study from Louisiana State University measured about 13 to 18% crude fat on a dry-matter basis in nymph and adult dubia. That is above the 3 to 6% the study cites from the Merck Veterinary Manual for omnivorous reptiles. The study's authors note that the reptile figures are not evidence based. They also suggest that captive reptiles, which spend little effort catching prey, may do better on less calorie-dense food.4
VCA singles out waxworms and superworms as high in fat and says they should not be fed daily.2 For an adult, cut the number of insect meals first. Follow the adult schedule above and keep greens available every day. If your dragon looks heavy or its appetite changes, ask a reptile veterinarian to check its body condition.
When to size up
Move to the next size when both of these are true:
- Your dragon's eye gap has grown past the top of its current size range.
- It eats the current size quickly and without effort.
ARAV notes that prey size rises as the dragon grows.1 Change one size at a time, and mix a few of the new size into a batch of the old one for the first week. If your dragon struggles, gapes, or refuses the larger roach, go back down.
A growing dragon goes through dubia quickly. If you feed weekly, subscribe and save delivers every 1, 2 or 3 months at 15% off, and deliveries of $35 or more ship free. You can skip, pause, or cancel from your customer account.
Before you feed
Size is one part of a good feeder. ARAV and VCA both say to gut load insects before feeding and to dust them with a calcium powder.1,2 The LSU study found that a high-calcium diet raised the calcium-to-phosphorus ratio of dubia, while a low-calcium commercial diet did not.4 Our guide on how to gut load feeder insects covers what to feed and for how long. For keeping your roaches alive between meals, see dubia roach care for keepers who feed them out. For how dubia compare with other feeders, read the best feeder insects for bearded dragons.
Dubia sizes for leopard geckos and other lizards
Leopard geckos are smaller than bearded dragons, so they need smaller dubia. VCA lists dubia roaches among suitable insects for leopard geckos. It recommends feeding juveniles every one to two days and adults two to three times a week.5 We found no veterinary source that sets a prey size for leopard geckos. Keepers apply the same eye-gap habit, and it is a sensible cap.
- Start hatchling and young leopard geckos on the smallest roaches in a box of Small dubia.
- For adults, measure the eye gap. Our Small and Medium sizes cover 1/4 to 3/4 in. Measure again before you try Large.
Our guide to the best feeder insects for leopard geckos covers the rest of their diet.
For other insect-eating lizards, such as blue-tongued skinks and fat-tailed geckos, the same measuring method works. Measure the eye gap, pick the size at or under it, and ask a reptile veterinarian for a feeding schedule that fits the species and the animal.
Still have questions about sizes or orders? See the feeder FAQ.
Sources
- Donoghue S, Klingenberg R; updated by Janusz M (2012) and Keller LC, Strunk A (2015). How to keep your bearded dragon healthy, happy and safe! Companion Reptile Care Series. Association of Reptilian and Amphibian Veterinarians, published by the North American Veterinary Community.
- Rich G, Hess L, Axelson R. Bearded dragons: feeding. VCA Animal Hospitals, LifeLearn Animal Health. Updated 2026.
- Divers SJ, Comolli JR. Nutritional, metabolic, and endocrine diseases of reptiles. Merck Veterinary Manual, Merck and Co. Full review 2025.
- Barras E, Boykin KL, Aguilar MG, Lex Z, Bitter A, Mitchell MA. 2025. Effect of commercial diets on the nutritional value and mortality rates of dubia roaches (Blaptica dubia). Journal of Herpetological Medicine and Surgery 35(3):176 to 191.
- Rich G. Leopard geckos: care and feeding. VCA Animal Hospitals, LifeLearn Animal Health. Updated 2024.
