Mass and Weight · Unit Converter

Convert Attogram to Ratti

Convert attograms to rattis instantly. 1 attogram = 8.230453e-18 ratti — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Ratti to Attogram 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

Attogram

What is a attogram?

An attogram (ag) equals 10^-21 kilogram.

Origin of the attogram

From the SI prefix 'atto-' (from Danish 'atten', eighteen).

Where it is used

Frontier nanoscience and single-molecule mass detection.

When and where it was developed

The atto- prefix was adopted by the CGPM in 1975.

Indian / South Asian

Ratti

What is a ratti?

The ratti equals about 0.1215 gram, the smallest traditional South Asian weight.

Origin of the ratti

Based on the seed of the Gunja plant (Abrus precatorius), or 'raktika' in Sanskrit.

Where it is used

Gemstones and gold in Indian and South Asian jewelry.

When and where it was developed

One of the oldest weight units of the Indian subcontinent, later standardized.

Attogram to Ratti conversion formula

Note: this conversion uses a generally accepted modern value. Historical and regional definitions of this unit varied across times and places.

The relationship between attograms and rattis:

1 ag = 8.230453e-18 ratti

1 ratti = 1.215e+17 ag

To convert attograms to rattis, multiply the value in attograms by 8.230453e-18. To reverse, multiply rattis by 1.215e+17.

How to use this converter

Type a value into the calculator. The result in rattis updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Ratti to Attogram converter for the reverse direction.

Step-by-step: convert attograms to rattis

Write down the value in attograms (ag).
Multiply that value by the factor 8.230453e-18.
The product is the equivalent value in rattis (ratti).
To reverse, multiply the ratti value by 1.215e+17.

Worked examples

Example 1 — Convert 1 ag to ratti:
1 × 8.230453e-18 = 8.230453e-18 ratti

Example 2 — Convert 100 ag to ratti:
100 × 8.230453e-18 = 8.230453e-16 ratti

Real-world example — Spanning sub-micron to micron scale

Crossing from attograms to rattis is the everyday workflow of microscopy and semiconductor engineering — a measurement of 1000 attograms translates to a much more compact value in rattis that fits the scale of biological cells and process nodes.

1000 ag × 8.230453e-18 = 8.230453e-15 ratti

Real-world example — Sub-visible-light wavelength

500 attograms (the green-yellow visible band) equals 0.5 rattis — the canonical conversion in optics between wavelength specifications and micron-scale lens-coating thicknesses.

500 ag × 8.230453e-18 = 4.115226e-15 ratti

Attogram to Ratti conversion table

Standard reference values for converting attograms to rattis:

Attogram [ag]	Ratti [ratti]
0.01	8.230453e-20
0.1	8.230453e-19
1	8.230453e-18
2	1.646091e-17
3	2.469136e-17
4	3.292181e-17
5	4.115226e-17
10	8.230453e-17
20	1.646091e-16
30	2.469136e-16
40	3.292181e-16
50	4.115226e-16
100	8.230453e-16
500	4.115226e-15
1000	8.230453e-15

Frequently asked questions

How many rattis is 1 attogram?

1 attogram equals 8.230453e-18 ratti.

How do I convert attograms to rattis?

Multiply the value in attograms by 8.230453e-18 to get rattis.

How do I convert rattis back to attograms?

Multiply the value in rattis by 1.215e+17, or use the Ratti to Attogram converter.

How many rattis is 100 attograms?

100 attograms equals 8.230453e-16 rattis, because 100 × 8.230453e-18 = 8.230453e-16.

Convert Attogram to other weight units

Show all Attogram conversions

Metric / SI (17 units)

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

Avoirdupois (15 units)

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

Troy & Apothecary (10 units)

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

Indian / South Asian (6 units)

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

Scientific / Atomic (9 units)

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

Astronomical (4 units)

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

Biblical / Ancient (14 units)

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

Force / Engineering (5 units)

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

Sources & references

Conversion factor (1 ag = 8.230453e-18 ratti) 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 Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.

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