Why Average DNA Results?
Different testing companies may report slightly different ancestry percentages for the same person because each uses distinct reference datasets and algorithms.
By averaging results from multiple companies, you can form a broader picture of your heritage.
This calculator lets you enter up to two sets of percentages for three regions. It returns the combined values and computes a diversity score using a common ecological formula.
Formula for Combined Percentages
The average percentage for each region is calculated by summing the two values and dividing by two:
where
and
are the percentages from tests 1 and 2 for region
.
Next, we calculate a diversity score inspired by Simpson’s Diversity Index:
The diversity score ranges from 0 (all ancestry from a single region) to close to 1 (even mix across regions).
It provides a simple way to visualize how varied your genetic background might be across the categories you entered.
Worked Example
If Test 1 reports 40% Region A, 35% Region B, 25% Region C and Test 2 reports 45% Region A, 30% Region B, 25% Region C,
the averages are 42.5%, 32.5%, and 25%. Converting to decimals and applying the formula gives:
1 − (0.425² + 0.325² + 0.25²) ≈ 0.67.
Example Table
Example inputs and averaged ancestry percentages
| Region |
Test 1 |
Test 2 |
Average |
| Region A |
40% |
45% |
42.5% |
| Region B |
35% |
30% |
32.5% |
| Region C |
25% |
25% |
25% |
Interpreting Your Results
Remember that DNA tests provide estimates, not absolute truths. Each company uses proprietary reference populations, and results can change as databases grow.
While the percentages are interesting, they can’t capture the entirety of cultural heritage. Family stories, traditions, and historical context add nuance beyond what genetics reveal.
If two tests disagree significantly, averaging them might soften extremes, but you should also read about each company’s methodology.
Some specialize in certain regions or use more samples from one area than another. The diversity score simply quantifies how balanced your ancestry appears across the three categories you entered.
Limitations and Ethical Considerations
This tool is for educational and entertainment purposes. Genetic ancestry testing raises privacy concerns because it involves sensitive biological data.
Before sharing your results online, consider the implications for you and your relatives. Data breaches or changes in company policy could expose information you intended to keep private.
Another caveat is that ancestry tests are less precise for people with ancestors from underrepresented regions.
If few samples from your heritage are in a company’s database, the percentages may be more speculative. Therefore, always interpret results in context.
A Broader Perspective
Many genealogists combine DNA results with traditional record searches—birth certificates, immigration documents, and oral histories.
By pairing genetic evidence with paper trails, you can construct a richer family narrative.
You might discover connections to historical events or migratory patterns. Studying how your ancestors moved across continents can foster a deeper appreciation for different cultures.
Even if you don’t uncover long-lost relatives, exploring ancestry can create a sense of belonging and curiosity about the past.
It’s a reminder that each of us carries stories from countless generations. Whether you choose to frame your heritage in percentages, stories, or a blend of both, celebrate the diversity that makes you unique.
Major DNA Testing Companies
Examples of major DNA testing companies and features
| Company |
Regions Reported |
Notable Features |
| 23andMe |
~2,000 |
Health reports, large database |
| AncestryDNA |
~1,800 |
Family tree integration |
| MyHeritage |
~2,100 |
Global user base, chromosome browser |
Each company updates its reference panels periodically, so percentages may change as databases grow.
Some tools, like chromosome browsers, allow you to inspect which segments of your genome align with specific populations, revealing more nuance than headline percentages alone.
Extending Beyond Three Regions
The calculator focuses on three regions for simplicity, but you can adapt the averages manually for additional categories.
For example, if you have data for five regions, average each pair separately and then compute the diversity score by summing the squares of all five averaged percentages.
The formula generalizes to any number of regions:
Where is the number of regions.
The more evenly distributed your percentages, the closer the diversity score approaches one.
Experimenting with additional data can highlight distant ancestries that make up only a sliver of your genome.
Related Calculators
Explore more genetics tools such as the DNA Sequencing Coverage Calculator for lab planning or the DNA Codon Translation Calculator when studying genes in detail.