81/40

Interval information

Ratio	81/40
Factorization	2-3 × 34 × 5-1
Monzo	[-3 4 -1⟩
Size in cents	1221.506¢
Name	syntonic octave
Color name	g8, gu octave
FJS name	[math]\displaystyle{ \text{P8}_{5} }[/math]
Tenney height (log2 nd)	11.6618
Weil height (log2 max(n, d))	12.6797
Wilson height (sopfr(nd))	23
Harmonic entropy (Shannon, [math]\displaystyle{ \sqrt{nd} }[/math])	~4.11673 bits
Open this interval in xen-calc

The ratio of 81/40 is the distance between the 81st and 40th harmonic, which can be seen as an octave that is augmented by a syntonic comma (81/80). This interval spans the size of about 1221.5 cents.