DNA double helix
DNA is the molecule that stores hereditary information in living organisms. Two nucleotide strands wind around one another to form its double helix.
How big is it?
2 nm · helix diameter
Helix diameter · representative
A little perspective
DNA double helix vs Glucose molecule: length comparison
The helix diameter of a DNA double helix is about 2 times the characteristic size of a glucose molecule.
DNA is the molecule that stores hereditary information in living organisms.
A glucose molecule is a simple sugar used by living cells as a source of chemical energy.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions.
Measurements, assumptions & sources +
DNA double helix
Helix diameter: 2 nm; representative.
A 2 nm diameter scale for B-form double-stranded DNA. The pictured strand length is illustrative, not the selected measurement.
University of Utah — Cell size and scale
The marked helix diameter is calibrated. Unmeasured illustration details are representative.
Glucose molecule
Characteristic size: 1 nm; representative.
A one-nanometre scale model of a glucose molecule; orientation affects its span.
University of Utah — Cell size and scale
The marked characteristic size is calibrated. Unmeasured illustration details are representative.
Use the visual comparison to explore its scale, then check the measurements and sources.
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Why this measurement?
Why we use 2 nm
We compare the helix diameter of a DNA double helix. This is a representative comparison value; individual specimens or conditions can vary.
A 2 nm diameter scale for B-form double-stranded DNA. The pictured strand length is illustrative, not the selected measurement.
The marked horizontal span follows the measured feature, not the edges of the image. How calibrated comparisons work →
Recorded properties
Dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 2 nm | Not recorded | representative |
Around this scale
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valueMicroscopic objectsGlucose molecule1 nmCharacteristic sizeA glucose molecule is a simple sugar used by living cells as a source of chemical energy.
Nearest higher valueMicroscopic objectsIgG antibody molecule14.5 nmRepresentative maximum molecular spanAn IgG antibody molecule is a Y-shaped protein produced by the immune system to identify and neutralise foreign substances.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- University of Utah — Cell size and scaleApproximate biological size regimes. Atlas specimens and geometric assumptions are individually labelled.
More ways to see it
Curated comparisons
There’s always another scale
Follow your curiosity.
Fundamental physicsProton1.682 fmA proton is a positively charged particle found in the nucleus of atoms, made up of quarks.
MicroscopicCell10 µmA cell is the basic structural unit of living organisms.
PeopleHair70 µmA hair is a slender strand of protein that grows from the skin of humans and other mammals.MicroscopicGlucose molecule1 nmA glucose molecule is a simple sugar used by living cells as a source of chemical energy.
MicroscopicWater molecule280 pmA water molecule is a group of two hydrogen atoms bonded to one oxygen atom.MicroscopicIgG antibody molecule14.5 nmAn IgG antibody molecule is a Y-shaped protein produced by the immune system to identify and neutralise foreign substances.
MicroscopicRibosome25 nmA ribosome is a molecular machine that builds proteins by reading instructions carried by messenger RNA.
Fundamental physicsBohr radius52.92 pmThe Bohr radius is a fundamental physical constant representing the most probable distance between the nucleus and the electron in a hydrogen atom according to early quantum theory.