How to use the autosomal recessive child risk calculator
Estimate the chance a child has an autosomal recessive condition and is a carrier, from each parent carrier probability. Enter probability parent 1 is a carrier, probability parent 2 is a carrier in the fields above; the chance child is affected, chance child is a carrier are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “recessive disease risk”, “carrier risk for child”, “autosomal recessive inheritance probability”, “calculate autosomal recessive child risk”, “find chance child is affected”.
Formula
Variables
- pc1 — Probability parent 1 is a carrier
- pc2 — Probability parent 2 is a carrier
Worked example
With probability parent 1 is a carrier = 0.02, probability parent 2 is a carrier = 0.02, the calculator gives chance child is affected ≈ 0.01 %; chance child is a carrier ≈ 1.98 %.
Frequently asked questions
What is the autosomal recessive child risk calculator used for?
Estimate the chance a child has an autosomal recessive condition and is a carrier, from each parent carrier probability. It helps with questions such as “recessive disease risk”, “carrier risk for child”, “autosomal recessive inheritance probability”.
What is the formula for the autosomal recessive child risk calculation?
Chance child is affected (%) = 100 × pc1 × pc2 × 0.25. Chance child is a carrier (%) = 100 × 0.5 × (pc1+pc2-pc1 × pc2). Here pc1 is probability parent 1 is a carrier, pc2 is probability parent 2 is a carrier.
What inputs do I need for the autosomal recessive child risk calculator?
You need probability parent 1 is a carrier, probability parent 2 is a carrier. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the autosomal recessive child risk calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the autosomal recessive child risk result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.