Gecko Feeding Calculator

Leopard geckos eat daily when young and every other day as adults; crested geckos get a complete diet daily

How much and how often to feed a gecko depends on the species. Leopard geckos are insectivores, so they eat live insects. The RSPCA advises feeding juveniles every day and adults every other day. Crested geckos are omnivores: they get a complete crested gecko diet (CGD) every day, with insects added once or twice a week (PetMD, RVC).

The veterinary sources checked give no formula for working out insect numbers or grams of CGD from body weight. What they do give is a rule to offer small amounts and remove anything not eaten within 30 minutes (RVC), plus food size limits. Pick a species, life stage and feeding interval, and this calculator shows a 2-week calendar of insect and CGD days and calcium and multivitamin days. It also compares enclosure temperature, humidity and weight with each source's range. For an adult leopard gecko first fed on October 22, 2026 and fed every other day, the 2-week total is 7 insect feedings, 7 calcium dustings and 2 multivitamin dustings.

Why it helps to plan feedings ahead

Insects alone do not give a gecko enough calcium. According to the Merck Veterinary Manual, insects such as crickets and mealworms contain only 0.03–0.3% calcium but 0.8–0.9% phosphorus, so the calcium to phosphorus ratio has to be corrected before they are fed. That is why keepers dust insects with calcium powder and gut-load them with nutritious food for a day or two beforehand. The RSPCA describes metabolic bone disease (MBD), caused by too little calcium, as a condition needing urgent veterinary care.

Supplements change from day to day rather than staying the same at every feeding, so they are easy to forget when you rely on memory. Setting a 2-week calendar once helps in situations like these:

• Bringing a new gecko home and deciding on a feeding interval and supplement order
• Switching the interval when a growing gecko reaches adulthood
• Installing new UVB lighting and moving to calcium without D3
• Sharing feeding duties in a household, by copying the 2-week plan for everyone to follow
• Checking temperature and humidity first when a gecko is not eating well

How the calculation works

First, choose a feeding interval. Even for the same species and life stage, each source recommends a different interval, so the interval buttons in the calculator name the source behind each one.

Once an interval is chosen, the calendar is built with these rules:

1. The first feeding date is day 0, and 14 days are counted.
2. For leopard geckos, insect days follow the interval you choose: daily, every other day (days 0, 2, 4…), 3× a week (days 0, 2 and 4 of each 7-day cycle) or 2× a week (days 0 and 3 of each 7-day cycle).
3. For crested geckos, CGD is placed every day, and insects either 1× a week (day 0 of each 7-day cycle) or 2× a week (days 0 and 3). Insects can also be left out.
4. Calcium follows PetMD. Leopard geckos are dusted on every second insect day, and crested geckos on every insect day. With UVB lighting on, the plan switches to calcium without D3.
5. A multivitamin is added on the first calcium day of every 7 days. This is the lower end of the 1–2× a week that PetMD advises.

Portion and food size

Offer a leopard gecko 1–2 insects at a time and watch whether they are eaten before adding more (PetMD). For an adult crested gecko, an insect day means 5–10 crickets or 3–4 worms (PetMD), and CGD is mixed with water as the label directs and served right away. For both species, remove insects not eaten within 30 minutes (RVC). Insects should be smaller than the gap between the eyes for a leopard gecko, and smaller than the widest part of the head for a crested gecko (PetMD).

Example: 2 weeks from October 22, 2026

These are the 2-week totals for six setups with the first feeding on October 22, 2026. Choose the same setup in the calculator and the total line under the calendar shows the same numbers.

In the second row, an adult leopard gecko fed every other day, the insect days are October 22, 24, 26, 28 and 30, and November 1 and 3. The multivitamin goes on the first calcium day of week one, October 22, and the first calcium day of week two, October 30. In the first row, a growing leopard gecko fed daily gets insects 14 times, but calcium only every second day, so 7 times.

Food types and how to choose

For crested geckos, the RSPCA lists blueberries, pears, papaya, strawberries and mango as fruit that can be offered. The RVC also describes feeding fruit and dark leafy greens daily with insects 1–2× a week in place of CGD. Whether you use CGD or fruit, dust the insects with a supplement.

Using calcium, D3 and multivitamins

UVB lets reptiles make vitamin D3 in the body, which is needed to store and use calcium (RSPCA). The RVC considers UVB lighting beneficial for both species and advises a low-output lamp, such as 6%, on for about 12 hours a day. Dust supplements lightly (RSPCA) and offer the dusted insects right away (RVC). The Merck Veterinary Manual also describes feeding insects a diet with 12% calcium starting 3 days before they are fed.

Enclosure temperature and humidity

Reptiles regulate body temperature using outside heat sources (RVC). So if a gecko is not eating well, check the temperature before changing the food. The enclosure checklist in the calculator draws the ranges in the tables below as bands and counts how many of them your measured value falls within. Values written as "about" are not ranges, so they appear only as a dot on the band and are left out of the count.

The sources differ widely for crested geckos. PetMD keeps the warm side low at 72–75 °F (22.2–23.9 °C) and warns against leaving the gecko long above 80 °F (26.7 °C), while the RSPCA sets the basking area at 78.8–82.4 °F (26–28 °C). Humidity also varies: 40–50% from the RSPCA, 50–70% from the RVC and 70–80% from PetMD. Measure temperature at each location with a digital thermometer rather than as an enclosure average (RSPCA, RVC), and measure humidity with a hygrometer placed in the middle of the enclosure (RVC). The 69.8–80.6 °F (21–27 °C) range from LafeberVet is a temperature gradient for the whole enclosure, so it is not placed on the cool side row of the checklist.

Common mistakes

• Working out insect numbers from body weight. The sources checked give no such formula. The rule is to offer small amounts and give what is eaten.
• Feeding a leopard gecko fruit or vegetables. PetMD explains that a leopard gecko's body is not built to digest them.
• Feeding a crested gecko bananas. The RSPCA says bananas and citrus block calcium absorption and should be avoided.
• Using waxworms or morioworms as a staple. They are fatty and only an occasional treat (RVC).
• Keeping UVB on but still using calcium with D3. With proper UVB, D3 does not need to be supplemented (PetMD, RSPCA).
• Leaving leftover food in the enclosure. CGD spoils quickly, so clear it daily (RSPCA), and remove insects not eaten within 30 minutes (RVC).
• Checking the temperature in only one spot. Measure the warm side, the cool side and night separately to see the gradient.

When to see a vet

The RSPCA says abnormal droppings or constipation together with weight loss in a leopard gecko can be serious. In crested geckos, abnormal droppings or weight loss can also be a sign of parasites (RSPCA). If metabolic bone disease is suspected, get veterinary care right away (RSPCA). Even when nothing seems wrong, the RVC and PetMD recommend a health check once a year. Weighing on the same scale at the same time of day and keeping a record makes changes easier to spot.

Limits and cautions

• Sources differ on feeding intervals and temperatures. This calculator only places the chosen source's guidance on the calendar and does not judge which one is right.
• It does not calculate insect numbers or grams of CGD from weight or age, because the veterinary sources have no formula to base that on.
• The supplement pattern (calcium every second insect day for leopard geckos, multivitamin on the first calcium day of every 7 days) is one arrangement matched to PetMD's frequencies. If your supplement's label gives different directions, follow the label.
• You choose the life stage yourself. The leopard gecko weight band (LafeberVet's adult range) is for reference and does not decide the stage.
• The sources checked have no weight range for crested geckos, so the checklist draws no band for them.
• For a gravid female or a sick or recovering gecko, follow your vet's instructions instead of this schedule.

Reference date The sources were checked on October 22, 2026. PetMD's crested gecko guide was updated on November 14, 2025, its leopard gecko guide on May 8, 2026 and the VCA guide on August 19, 2024. Both RVC sheets were reviewed in December 2024. The two RSPCA guides carry no publication date.

Sources

• 01RSPCA: Leopard geckoJuveniles daily, adults every other day, food smaller than the head, light dusting with vitamins and calcium with a calcium dish always available, gut-loading 24–48 hours, 82.4–86 °F (28–30 °C), 75.2–78.8 °F (24–26 °C), humidity 30–40%
• 02RSPCA: Crested geckoCGD as a supplementary food, leftovers cleared daily, no citrus or bananas, no D3 needed with UV, 78.8–82.4 °F (26–28 °C), 68–75.2 °F (20–24 °C), night 64.4–68 °F (18–20 °C), humidity 40–50% (up to 80% when misted)
• 03PetMD: Crested Gecko Care SheetWritten by Maria Zayas DVM, reviewed by Ivan Alfonso DVM, updated 2025-11-14. CGD daily, insects 1–2× a week, adults 5–10 crickets or 3–4 worms, calcium (with D) and multivitamin 1–2× a week
• 04PetMD: Leopard Gecko Care SheetUpdated 2026-05-08. 1–2 insects at a time, food smaller than the gap between the eyes, supplements every second day, no D3 with UVB, no fruit or vegetables, 80–90 °F, 75–80 °F, humidity under 50%
• 05VCA Animal Hospitals: Leopard Geckos – Care and FeedingGregory Rich DVM, updated 2024-08-19. Juveniles every 1–2 days, adults 2–3× a week, phosphorus-free calcium and a calcium dish, night down to 70 °F (21 °C)
• 06Royal Veterinary College: Leopard gecko careReviewed December 2024. Basking about 89.6 °F (32 °C), cool side about 77 °F (25 °C), night not below about 68 °F (20 °C), humidity 30–40%, calcium alternated with vitamin and mineral supplement, uneaten insects removed after 30 minutes
• 07Royal Veterinary College: Crested gecko careReviewed December 2024. Usually a complete diet, insects 1–2× a week, basking about 82.4 °F (28 °C), cool side about 77 °F (25 °C), night not below about 68 °F (20 °C), humidity 50–70%
• 08LafeberVet: Basic Information Sheet: Leopard GeckoAdults once a day in the late afternoon, hatchlings 6–8 g, adult males 60–90 g, females as light as 45 g, warm spot 90 °F (32 °C), night 69.8–73.4 °F (21–23 °C), humidity 40–60%
• 09Merck Veterinary Manual: Nutrition in LizardsInsects contain 0.03–0.3% calcium and 0.8–0.9% phosphorus, so the calcium to phosphorus ratio is corrected before feeding; a 12% calcium diet fed to insects from 3 days before

Frequently asked questions

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