Mass and Weight · Unit Converter

Convert Nanogram to Dram (apothecary/troy)

Convert nanograms to drams (apothecary/troy) instantly. 1 nanogram = 2.57206e-10 dram (apothecary/troy) — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Dram (apothecary/troy) to Nanogram converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Ashok Kumar K, Ph.D.

Mass and Weight category 2 min read Published June 10, 2026 Last reviewed June 10, 2026 Updated June 10, 2026

Units explained

Metric / SI

Nanogram

What is a nanogram?

A nanogram (ng) equals 10^-12 kilogram.

Origin of the nanogram

From the SI prefix 'nano-' (from Greek 'nanos', dwarf).

Where it is used

Molecular biology, forensics, and toxicology.

When and where it was developed

The nano- prefix entered the SI in 1960.

Troy & Apothecary

Dram (apothecary/troy)

What is a dram (apothecary/troy)?

The apothecary (troy) dram equals one-eighth of a troy ounce, about 3.888 grams.

Origin of the dram (apothecary/troy)

From the apothecaries' system rooted in the Greek 'drachma'.

Where it is used

Historical pharmacy and medicine compounding.

When and where it was developed

Part of the apothecaries' system of weights used through the 19th century.

Nanogram to Dram (apothecary/troy) conversion formula

The relationship between nanograms and drams (apothecary/troy):

1 ng = 2.57206e-10 dr ap

1 dr ap = 3.887935e+9 ng

To convert nanograms to drams (apothecary/troy), multiply the value in nanograms by 2.57206e-10. To reverse, multiply drams (apothecary/troy) by 3.887935e+9.

How to use this converter

Type a value into the calculator. The result in drams (apothecary/troy) updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Dram (apothecary/troy) to Nanogram converter for the reverse direction.

Step-by-step: convert nanograms to drams (apothecary/troy)

Write down the value in nanograms (ng).
Multiply that value by the factor 2.57206e-10.
The product is the equivalent value in drams (apothecary/troy) (dr ap).
To reverse, multiply the dram (apothecary/troy) value by 3.887935e+9.

Worked examples

Example 1 — Convert 1 ng to dr ap:
1 × 2.57206e-10 = 2.57206e-10 dr ap

Example 2 — Convert 100 ng to dr ap:
100 × 2.57206e-10 = 2.57206e-8 dr ap

Real-world example — Sub-micron to millimeter

500,000 nanograms converts to a small everyday quantity in drams (apothecary/troy) — useful when relating optical-wavelength specifications to physical mounting hardware.

500000 ng × 2.57206e-10 = 0.000128603 dr ap

Real-world example — From wavelengths to millimeter-scale objects

A value of one million nanograms sounds vast at the atomic scale but converts to a small everyday quantity in drams (apothecary/troy) — useful when relating optical-wavelength specifications to physical mounting hardware.

1000000 ng × 2.57206e-10 = 0.000257206 dr ap

Nanogram to Dram (apothecary/troy) conversion table

Standard reference values for converting nanograms to drams (apothecary/troy):

Nanogram [ng]	Dram (apothecary/troy) [dr ap]
0.01	2.57206e-12
0.1	2.57206e-11
1	2.57206e-10
2	5.144119e-10
3	7.716179e-10
4	1.028824e-9
5	1.28603e-9
10	2.57206e-9
20	5.144119e-9
30	7.716179e-9
40	1.028824e-8
50	1.28603e-8
100	2.57206e-8
500	1.28603e-7
1000	2.57206e-7

Frequently asked questions

How many drams (apothecary/troy) is 1 nanogram?

1 nanogram equals 2.57206e-10 dram (apothecary/troy).

How do I convert nanograms to drams (apothecary/troy)?

Multiply the value in nanograms by 2.57206e-10 to get drams (apothecary/troy).

How do I convert drams (apothecary/troy) back to nanograms?

Multiply the value in drams (apothecary/troy) by 3.887935e+9, or use the Dram (apothecary/troy) to Nanogram converter.

How many drams (apothecary/troy) is 100 nanograms?

100 nanograms equals 2.57206e-8 drams (apothecary/troy), because 100 × 2.57206e-10 = 2.57206e-8.

Convert Nanogram to other weight units

Show all Nanogram conversions

Metric / SI (17 units)

Nanogram to Attogram (ag) Nanogram to Femtogram (fg) Nanogram to Picogram (pg) Nanogram to Microgram (µg) Nanogram to Milligram (mg) Nanogram to Centigram (cg) Nanogram to Decigram (dg) Nanogram to Gram (g) Nanogram to Dekagram (dag) Nanogram to Hectogram (hg) Nanogram to Kilogram (kg) Nanogram to Quintal (metric) (q) Nanogram to Metric Ton (t) Nanogram to Gigagram (Gg) Nanogram to Teragram (Tg) Nanogram to Petagram (Pg) Nanogram to Exagram (Eg)

Avoirdupois (15 units)

Nanogram to Grain (gr) Nanogram to Dram (avoirdupois) (dr) Nanogram to Ounce (oz) Nanogram to Pound (lb) Nanogram to Clove (clove) Nanogram to Stone (US) (st) Nanogram to Stone (UK) (st) Nanogram to Quarter (US) (qr) Nanogram to Quarter (UK) (qr) Nanogram to Hundredweight (US) (cwt) Nanogram to Hundredweight (UK) (cwt) Nanogram to Wey (wey) Nanogram to Kilopound (kip) (kip) Nanogram to Ton (short, US) (sh tn) Nanogram to Ton (long, UK) (long tn)

Troy & Apothecary (10 units)

Nanogram to Point (1/100 carat) (pt) Nanogram to Carat (metric) (ct) Nanogram to Scruple (apothecary) (s ap) Nanogram to Pennyweight (dwt) Nanogram to Momme (mom) Nanogram to Mace (mace) Nanogram to Dram (apothecary/troy) (dr ap) Nanogram to Troy Ounce (oz t) Nanogram to Tael (tael) Nanogram to Pound (troy/apothecary) (lb t)

Indian / South Asian (6 units)

Nanogram to Ratti (ratti) Nanogram to Masha (masha) Nanogram to Tola (tola) Nanogram to Chittack (Chatank) (chittack) Nanogram to Seer (Ser) (seer) Nanogram to Maund (Mann) (maund)

Scientific / Atomic (9 units)

Nanogram to Electron Mass (rest) (me) Nanogram to MeV/c2 (MeV/c²) Nanogram to Muon Mass (mµ) Nanogram to Atomic Mass Unit (u) Nanogram to Proton Mass (mp) Nanogram to Neutron Mass (mn) Nanogram to Deuteron Mass (md) Nanogram to Carbon-12 Atom Mass (C-12) Nanogram to Planck Mass (mP)

Astronomical (4 units)

Nanogram to Lunar Mass (Moon) (M☾) Nanogram to Earth's Mass (M⊕) Nanogram to Jupiter Mass (MJ) Nanogram to Sun's Mass (M☉)

Biblical / Ancient (14 units)

Nanogram to Lepton (Biblical Roman) (lepton) Nanogram to Quadrans (Biblical Roman) (quadrans) Nanogram to Assarion (Biblical Roman) (assarion) Nanogram to Gerah (Biblical Hebrew) (gerah) Nanogram to Drachma (Biblical Greek) (drachma) Nanogram to Denarius (Biblical Roman) (denarius) Nanogram to Bekan (Biblical Hebrew) (bekah) Nanogram to Didrachma (Biblical Greek) (didrachma) Nanogram to Shekel (Biblical Hebrew) (shekel) Nanogram to Tetradrachma (Biblical Greek) (tetra) Nanogram to Mina (Biblical Greek) (mina) Nanogram to Mina (Biblical Hebrew) (mina) Nanogram to Talent (Biblical Greek) (talent) Nanogram to Talent (Biblical Hebrew) (talent)

Force / Engineering (5 units)

Nanogram to Poundal (pdl) Nanogram to Ton (assay) (US) (AT) Nanogram to Ton (assay) (UK) (AT) Nanogram to Kilogram-force square second/meter (hyl) Nanogram to Slug (slug)

Sources & references

Conversion factor (1 ng = 2.57206e-10 dr ap) verified against the following authoritative sources:

BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.

Results are provided for general reference. Verify critical measurements against an authoritative standard.