Mass and Weight · Unit Converter

Convert Pennyweight to Atomic Mass Unit

Convert pennyweights to atomic mass unit instantly. 1 pennyweight = 9.365469e+23 atomic mass unit — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Atomic Mass Unit to Pennyweight 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 Last reviewed Updated

Units explained

Troy & Apothecary

Pennyweight

What is a pennyweight?

The pennyweight (dwt) equals one-twentieth of a troy ounce, 24 grains (about 1.555 g).

Origin of the pennyweight

From the mass of a medieval English silver penny; symbol dwt from 'denarius weight'.

Where it is used

Jewelry making and precious-metal scrap valuation in the US.

When and where it was developed

Derived from the medieval English coinage system.

Scientific / Atomic

Atomic Mass Unit

What is a atomic mass unit?

One unified atomic mass unit (u) is defined as 1/12 the mass of a carbon-12 atom, about 1.6605E-27 kg.

Origin of the atomic mass unit

Introduced to give atomic and molecular masses convenient numerical values.

Where it is used

Atomic, molecular, and nuclear physics and chemistry.

When and where it was developed

The unified (carbon-12) scale was adopted by IUPAC and IUPAP in 1960-1961.

Pennyweight to Atomic Mass Unit conversion formula

The relationship between pennyweights and atomic mass unit:

1 dwt = 9.365469e+23 u
1 u = 1.067752e-24 dwt

To convert pennyweights to atomic mass unit, multiply the value in pennyweights by 9.365469e+23. To reverse, multiply atomic mass unit by 1.067752e-24.

How to use this converter

Type a value into the calculator. The result in atomic mass unit updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Atomic Mass Unit to Pennyweight converter for the reverse direction.

Step-by-step: convert pennyweights to atomic mass unit

  1. Write down the value in pennyweights (dwt).
  2. Multiply that value by the factor 9.365469e+23.
  3. The product is the equivalent value in atomic mass unit (u).
  4. To reverse, multiply the atomic mass unit value by 1.067752e-24.

Worked examples

Example 1 — Convert 1 dwt to u:
1 × 9.365469e+23 = 9.365469e+23 u

Example 2 — Convert 100 dwt to u:
100 × 9.365469e+23 = 9.365469e+25 u

Real-world example — Centimeter to wavelength scale

One pennyweight equals 10 million atomic mass unit. Physics curricula use this kind of conversion to relate everyday measurements to atomic and optical scales.

1 dwt × 9.365469e+23 = 9.365469e+23 u

Real-world example — Small-scale to atomic-scale

One pennyweight equals 10 million atomic mass unit — useful for physics curricula that relate everyday measurements to atomic and optical scales.

1 dwt × 9.365469e+23 = 9.365469e+23 u

Pennyweight to Atomic Mass Unit conversion table

Standard reference values for converting pennyweights to atomic mass unit:

Pennyweight [dwt]Atomic Mass Unit [u]
0.019.365469e+21
0.19.365469e+22
19.365469e+23
21.873094e+24
32.809641e+24
43.746188e+24
54.682735e+24
109.365469e+24
201.873094e+25
302.809641e+25
403.746188e+25
504.682735e+25
1009.365469e+25
5004.682735e+26
10009.365469e+26

Frequently asked questions

How many atomic mass unit is 1 pennyweight?
1 pennyweight equals 9.365469e+23 atomic mass unit.
How do I convert pennyweights to atomic mass unit?
Multiply the value in pennyweights by 9.365469e+23 to get atomic mass unit.
How do I convert atomic mass unit back to pennyweights?
Multiply the value in atomic mass unit by 1.067752e-24, or use the Atomic Mass Unit to Pennyweight converter.
How many atomic mass unit is 100 pennyweights?
100 pennyweights equals 9.365469e+25 atomic mass unit, because 100 × 9.365469e+23 = 9.365469e+25.

Convert Pennyweight to other weight units

Show all Pennyweight conversions
Metric / SI (18 units)
Avoirdupois (15 units)
Troy & Apothecary (9 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Force / Engineering (5 units)

Sources & references

Conversion factor (1 dwt = 9.365469e+23 u) verified against the following authoritative sources:

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