Rat Coat Color Genetics Calculator

What is the Rat Coat Color Genetics Calculator?

The Rat Coat Color Genetics Calculator predicts possible offspring coat colors from parent rats genetics. Understanding likely outcomes helps breeders set expectations and avoid pairing combinations that could carry unwanted or harmful traits.

A well-cared-for rat usually lives somewhere between 2 and 3 years. Diet-wise they are an omnivore, which shapes almost every feeding decision you make. Rats are intensely social and must be kept in same-sex pairs or groups. They need a tall wire cage with solid levels, daily out-of-cage time, and constant novelty since they bore quickly. Keep an eye out for mycoplasma respiratory disease, mammary tumours in females, pituitary tumours. These are the conditions rats are most commonly seen for.

How does the Rat Coat Color Genetics Calculator work?

The prediction uses a simplified model of the most influential genes for the trait in question. Real genetics can involve additional modifier genes not captured here, especially for complex or rare morphs. The math is only as good as what you feed it, so an accurate, recent input matters more than the formula itself.

Factors that matter

• The genotype (not just visible appearance) of both parents, which isn't always knowable without testing
• Whether either parent carries a recessive trait that isn't visibly expressed
• Modifier genes not included in this simplified model, which can shift real-world results
• Litter or clutch size: since probabilities describe averages across many offspring, not a single guaranteed outcome

How do you use the Rat Coat Color Genetics Calculator?

1. Pick your parent A — Base color (dark, light)
2. Pick your parent B — Base color (dark, light)
3. Pick your parent A — Dilution (full, diluted)
4. Pick your parent B — Dilution (full, diluted)
5. Press Calculate, then read the result alongside the sources listed below

If two people care for your rat, agree on one method and stick to it. Half of all confusing results come from measuring differently each time.

For related questions, see the other genetics tools or browse every rat tool.

Before you rely on this

Two rats with identical numbers on paper can still need different care. Breed or line, body condition, activity level and any existing health conditions all pull the real answer away from the average. If your rat has a diagnosed condition, is pregnant, or is very young or very old, treat the figure here as the loosest of guides and let your vet set the actual target.