Find your ideal breeder count, when your colony covers all feeder demand, monthly gutload budget, and break-even vs buying online — all from your own inputs.
Select species and age for typical feeder presets, then adjust count/week to match your pet's actual intake.
Add each reptile you keep, select its species and life stage to load typical feeder presets (you can override these with your pet's actual intake), then adjust the biology and cost fields to match your setup. Results update instantly.
Dubia roaches (Blaptica dubia) are ovoviviparous — females incubate eggs internally and give live birth. At an optimal colony temperature of 85–95°F (29–35°C), a female's gestation cycle runs approximately 65 days, after which she gives birth to an average of 25 nymphs (range: 20–40), then mates again within about a week. Nymphs pass through 7 instars and reach adulthood in roughly 5 months under warm, well-fed conditions.
The recommended male-to-female ratio is 1:4 (1 male per 4 females). Excess males cause territorial stress and reduce reproductive output. Adult females live approximately 18–24 months; males 12–18 months.
For casual keepers with one small reptile consuming 15–20 roaches/week, buying online may be more convenient than managing a colony. But for households with multiple animals or heavy feeder use (50+ roaches/week), a self-sustaining colony typically breaks even within 3–6 months and saves significant money long-term. The calculator's break-even tab shows your exact payoff timeline.
Divide your weekly feeder demand by each female's weekly output. A female produces ~25 nymphs every 65 days — roughly 2.7 nymphs per week before survival losses. At an 80% survival rate, each female delivers about 2.2 usable feeders per week. For 50 roaches/week, you need at minimum ~23 breeding females, plus a safety buffer of 20–30% on top of that.
Starting with adult, already-mated females, the first nymphs arrive in ~65 days. Those nymphs take a further ~5 months to reach breeding age. The colony is truly "generationally self-sustaining" — where colony-born nymphs are themselves breeding — in roughly 7–9 months from a cold start. Buying pregnant females or already-cycling breeders shortens this window considerably.
For light users (under 30 roaches/week) buying online or from a local expo is often more economical once you factor in heat, time, and startup costs. For moderate to heavy use, breeding pays off within 3–6 months. The key cost advantage is that colony running costs (gutload food + electricity) are typically well under the cost of buying equivalent volumes of roaches. Use the Cost & Break-Even tab to calculate your exact timeline.
The community-standard ratio is 1 male per 4 females (1:4). Acceptable ranges run from 1:3 (slightly more males, more genetic diversity) to 1:7 (maximum female density). Having too many males leads to territorial behaviour, stress, wing biting, and reduced reproductive output from females. Males can stay in the colony permanently — you don't need to remove them after mating.
Fresh produce should be offered 2–3 times per week in an amount the colony finishes within 24 hours. A rough guide: for every 100 adult-equivalent roaches, plan 50–100 g of fresh produce per feeding session, plus a dry chow base kept available at all times. The Gutload Budget tab in this calculator estimates your weekly and monthly quantities from your colony size and feeding frequency.
Dubia roaches cannot climb smooth plastic or glass, cannot fly (females are entirely flightless; males rarely fly), and require 85–95°F to breed — far above typical home temperatures. Escapees in a normal household will not establish a colony. However, a secure, smooth-sided tub remains best practice. Note: dubia roaches are not legal to keep in Florida, California, Louisiana, Alabama, or Hawaii in the US — check your local regulations.
The standard rule: feeders should be no larger than the space between your reptile's eyes. For baby bearded dragons or hatchling geckos, use 1/8–1/4" nymphs. Juvenile reptiles typically take 1/4–3/4" nymphs. Adult bearded dragons can eat large nymphs and adult roaches (1–1.5"). Oversized feeders risk impaction, a potentially fatal condition where the feeder blocks the digestive tract.