Enter breeding adult males and females, average brood size, and brood interval.
Everyday tool
Guppy Breeding Simulator
Explore guppy population growth from brood interval, fry survival, maturity, and separation.
Explore a breeding scenarioChange brood, survival, maturity, and separation assumptions.
GUPPYAssumptions matter
Each adult female is assumed to brood at the same interval. Surviving fry mature at the selected month and may breed afterward unless separated.
Population projectionScenario, not a promise
After 6 months1,722 fishAdults 138 · Juveniles 1,584
Now6—
1 mo50+44
2 mo94+44
3 mo138+44
4 mo424+286
5 mo952+528
6 mo1,722+770
Later generations also reproduce
Actual numbers can be far lower because brood size, survival, maturity, sex ratio, fertility, predation, and care conditions vary.
Complete guide
How to use Guppy Breeding Simulator
When to use it
Change starting adult males and females, average brood size, birth interval, fry survival, sex ratio, maturity, and separation month to estimate a month-by-month guppy population scenario.
01
Three-step workflow
- 1
Enter breeding adult males and females, average brood size, and brood interval.
- 2
Set fry survival, female ratio, maturity age, and projection length.
- 3
Optionally choose a separation month and review monthly total, adult, and juvenile estimates.
02
What to enter and check
Without separation, surviving fry enter the breeding population at the selected maturity month and can produce later generations.
This is an illustrative scenario with constant assumptions, not a stocking-density or rehoming schedule recommendation.
Practical example
Explore six months from two males and four females using 20 fry per 30-day brood, 55% survival, and maturity at three months.
How to read the result
This is an illustrative scenario with constant assumptions, not a stocking-density or rehoming schedule recommendation.
05
Before you use the result
- The model includes breeding by newly mature generations until the separation month, illustrating how quickly numbers can compound.
- Real reproduction and survival vary widely, and this result is not a stocking-density recommendation.
06
Frequently asked questions
How should I read the Guppy Breeding Simulator result?+
This is an illustrative scenario with constant assumptions, not a stocking-density or rehoming schedule recommendation.
What should I check for a more accurate Guppy Breeding Simulator result?+
Without separation, surviving fry enter the breeding population at the selected maturity month and can produce later generations. The model includes breeding by newly mature generations until the separation month, illustrating how quickly numbers can compound.
Is my input uploaded or stored?+
No. This tool processes input in your current browser, and Baro Tool does not store the source content or result on its server.