diff --git a/src/systems/cgs/include/mp-units/systems/cgs/cgs.h b/src/systems/cgs/include/mp-units/systems/cgs/cgs.h
index 5bd350ca..bbcea163 100644
--- a/src/systems/cgs/include/mp-units/systems/cgs/cgs.h
+++ b/src/systems/cgs/include/mp-units/systems/cgs/cgs.h
@@ -33,11 +33,11 @@ inline constexpr struct gram : decltype(si::gram) {} gram;
 inline constexpr struct second : decltype(si::second) {} second;
 inline constexpr struct gal : named_unit<"Gal", centimetre / square<second>> {} gal;
 inline constexpr struct dyne : named_unit<"dyn", gram * centimetre / square<second>> {} dyne;
-inline constexpr struct erg : named_unit<"erg", dyne / centimetre> {} erg;
+inline constexpr struct erg : named_unit<"erg", dyne * centimetre> {} erg;
 inline constexpr struct barye : named_unit<"Ba", gram / (centimetre * square<second>)> {} barye;
 inline constexpr struct poise : named_unit<"P", gram / (centimetre * second)> {} poise;
 inline constexpr struct stokes : named_unit<"St", square<centimetre> / second> {} stokes;
-inline constexpr struct kayser : decltype(1 / centimetre) {} kayser;
+inline constexpr struct kayser : named_unit<"K", 1 / centimetre> {} kayser;
 // clang-format on
 
 namespace unit_symbols {
@@ -50,6 +50,13 @@ inline constexpr auto dyn = dyne;
 inline constexpr auto Ba = barye;
 inline constexpr auto P = poise;
 inline constexpr auto St = stokes;
+inline constexpr auto K = kayser;
+
+// commonly used squared and cubic units
+inline constexpr auto cm2 = square<centimetre>;
+inline constexpr auto cm3 = cubic<centimetre>;
+inline constexpr auto s2 = square<second>;
+inline constexpr auto s3 = cubic<second>;
 
 }  // namespace unit_symbols