Grandparent DNA Testing: When and How It Works
Published January 28, 2026 · Medically reviewed by the partner laboratory's medical director, AABB-accredited relationship-testing laboratory
A grandparent DNA test compares one or both paternal grandparents against a child to determine the probability the alleged father is the biological father. When both grandparents test, results are typically 99%+ conclusive; a single grandparent gives 90–95%. It's the standard alternative when the alleged father is deceased, missing, or refuses testing.
When to use it
Best when the alleged father is unavailable — deceased, incarcerated, missing, or refusing. Also useful when a father has passed away and the family wants confirmation for inheritance or Social Security survivor benefits.
Ready to move forward? Order our $99 at-home test — AABB-accredited, results in 1–2 business days.
Statistical power
Two grandparents tested against the child usually returns 99%+ probability. One grandparent alone gives lower probability (90–95%) but is still meaningful, especially combined with a maternal sample.
How to order
Contact our team — we don't sell grandparent tests as a click-and-buy product because we want to walk you through the setup. Pricing typically runs $199–$299 depending on how many samples are needed.