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Sperm DNA fragmentation (DFI) calculator

What does my DFI result mean?

Q: My semen analysis was normal. Why test this?

Because a standard analysis assesses count, movement and shape — not the DNA inside. Some men with entirely normal parameters have high fragmentation, and it is one explanation for unexplained failure.

Q: Can DFI be improved?

Sometimes. Treating a varicocele or infection, stopping smoking, reducing heat exposure, and shorter abstinence intervals have all shown effects. Allow about three months for changes to appear, because of the production cycle.

Q: Do the thresholds mean the same across labs?

No. Different assays produce different numbers for the same sample. The bands here are indicative — use your laboratory’s own reference range.

What a DFI result means — and why a completely normal semen analysis does not rule out a problem here.

DNA fragmentation index

From your DFI report

These are example numbers. Replace them with yours, then press Calculate.

Example answer

18.0%

15–25%

Intermediate. Often reported as a grey zone where the clinical significance is genuinely debated.

This is a guide, not a diagnosis. Share the result with your doctor.

Your result on the scale

The ranges this calculator uses. Yours is highlighted.

Your numbers

Everything worked out from what you entered.

DNA fragmentation index: 18 %

What each result means

Your result is highlighted. Your own clinic's advice always comes first.

Your result<15%

Low fragmentation. DNA integrity is unlikely to be a limiting factor.

Your result15–25%

Intermediate. Often reported as a grey zone where the clinical significance is genuinely debated.

Your result25–30%

Raised. Associated in some studies with lower fertilisation and higher miscarriage rates, though the evidence is not uniform.

Your result30%+

High. Often prompts a look at modifiable factors — varicocele, infection, smoking, heat exposure — and sometimes a change in the ICSI approach.

Where this fits in your journey

The usual order, from trying to conceive to pregnancy. Not everyone needs every stage. This calculator belongs to stage 2.

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This calculator: What does my DFI result mean?

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How this is worked out

Compared to published rangesYour values checked against published reference limits. The source is named below; laboratory methods vary.

The DNA fragmentation index measures the proportion of sperm with damaged DNA. Below 15% is generally considered low and above 30% high, though thresholds differ by assay method — a normal semen analysis does not rule out high fragmentation.

About this calculator

?What it tells you

Sperm DNA damage, explained. What a DFI result means — and why a completely normal semen analysis does not rule out a problem here.

✓When to use it

After unexplained failure, or a normal analysis with poor outcomes

iWhat you need

DNA fragmentation index (%)

!What it cannot tell you

DFI thresholds are assay-specific. Use the reference range from the laboratory that ran your test.

Common questions

My semen analysis was normal. Why test this?

Because a standard analysis assesses count, movement and shape — not the DNA inside. Some men with entirely normal parameters have high fragmentation, and it is one explanation for unexplained failure.

Can DFI be improved?

Sometimes. Treating a varicocele or infection, stopping smoking, reducing heat exposure, and shorter abstinence intervals have all shown effects. Allow about three months for changes to appear, because of the production cycle.

Do the thresholds mean the same across labs?

No. Different assays produce different numbers for the same sample. The bands here are indicative — use your laboratory’s own reference range.

Sources

DFI thresholds vary substantially between assay methods (SCSA, TUNEL, comet, halosperm). Confirm which method your laboratory used before comparing against any published threshold.

In an emergency

If you have any of the warning signs listed here, don't wait for a test result or a calculator. Get help now.

112All emergencies, anywhere in India 108Ambulance

Also call your IVF clinic. Most clinics give an emergency number on your treatment or discharge sheet. Save it in your phone now, before you need it.