How many newtons is one dyne?

One dyne equals exactly 0.00001 newtons (10⁻⁵ N). Equivalently, one newton equals exactly 100,000 dynes.

Why is the dyne so much smaller than the newton?

The dyne is built on the gram and centimeter (the CGS system), while the newton is built on the kilogram and meter (SI). A gram is 1/1,000 of a kilogram and a centimeter is 1/100 of a meter, and those two scaling factors compound through the force formula (mass × acceleration) to produce the 100,000× difference.

Where do dynes still appear in modern measurements?

Surface tension is still very commonly reported in dynes per centimeter (dyn/cm) in chemistry, materials science, and industrial coating specifications — water's surface tension at room temperature is often quoted as about 72 dyn/cm — even though the equivalent SI unit (newtons per meter) is technically preferred.

Is CGS still used anywhere besides dynes?

CGS units persist in specific specialized fields — parts of electromagnetism in theoretical physics and astrophysics literature, and centimeter-gram-second conventions in some older chemistry and engineering references — but SI has replaced CGS as the general-purpose standard essentially everywhere else.

Guide

Dynes to newtons: converting CGS force to SI units

One dyne equals exactly 10⁻⁵ newtons — the force needed to accelerate a one-gram mass at one centimeter per second squared, a leftover from the CGS system that SI replaced for most other purposes.

By Buğra SözeriPublished September 25, 2026

The dyne belongs to the CGS system — centimeter, gram, second — which predates the SI system built on the meter, kilogram, and second. Both systems define force the same way conceptually, as mass times acceleration, but because their base units for mass and length differ by factors of 1,000 and 100 respectively, the resulting force units end up wildly different in scale.

The exact conversion

One dyne is defined as the force that accelerates a one-gram mass at one centimeter per second squared. Converting that definition into SI's kilogram-meter-second terms gives:

1 dyn = 0.00001 N (10⁻⁵ N)
1 N = 100,000 dyn

Why dynes persist in surface tension

Surface tension is a small force per unit length, and dynes per centimeter (dyn/cm) happens to produce convenient, easy-to-read numbers for common liquids — water's surface tension at room temperature is about 72 dyn/cm, a figure chemists and materials scientists have used for decades of published reference data. Converting that same measurement to the SI-preferred newtons per meter (N/m) produces a small decimal (0.072 N/m) that's less immediately readable, which is a practical reason dyn/cm has stuck around in coating, adhesive, and ink-wetting specifications even in otherwise SI-standardized industries.

Converting a force measurement

Dynes	Newtons
1 dyn	0.00001 N
1,000 dyn	0.01 N
100,000 dyn	1 N
1,000,000 dyn	10 N

Because the factor spans five orders of magnitude, a misplaced decimal point is the most common error when converting dyne-based data by hand — worth double-checking against a calculator rather than doing the shift mentally, especially for lab or QA data that will feed into a report.

Frequently asked questions

How many newtons is one dyne?: One dyne equals exactly 0.00001 newtons (10⁻⁵ N). Equivalently, one newton equals exactly 100,000 dynes.
Why is the dyne so much smaller than the newton?: The dyne is built on the gram and centimeter (the CGS system), while the newton is built on the kilogram and meter (SI). A gram is 1/1,000 of a kilogram and a centimeter is 1/100 of a meter, and those two scaling factors compound through the force formula (mass × acceleration) to produce the 100,000× difference.
Where do dynes still appear in modern measurements?: Surface tension is still very commonly reported in dynes per centimeter (dyn/cm) in chemistry, materials science, and industrial coating specifications — water's surface tension at room temperature is often quoted as about 72 dyn/cm — even though the equivalent SI unit (newtons per meter) is technically preferred.
Is CGS still used anywhere besides dynes?: CGS units persist in specific specialized fields — parts of electromagnetism in theoretical physics and astrophysics literature, and centimeter-gram-second conventions in some older chemistry and engineering references — but SI has replaced CGS as the general-purpose standard essentially everywhere else.

Sources & references

Authoritative references cited by this piece. Verified by Buğra Sözeri on the dates shown and re-checked at every deploy.

BIPM — SI Brochure, 9th edition (SI derived units and non-SI unit context) — Reference for how the newton relates to the earlier CGS system of units(as of 2026-09-25)