In this calculator, Harmony in Gradation is only used to calculate the Confidence Level of the estimated value, while the process of calculating the estimated value was using the linear trend method modified by Sigit Haryadi. The reference is Haryadi, S. (2018, March 29). Smart Estimation Ver-H.1.0.

The advantage of this method is to remain accurate regardless of the sample size and may ignore the past value that is considered irrelevant. Suppose you have the following data at t = 1, 2, 3 …….. N is Y = 1, 2, 10000, 4 ….. N. Then you may enter the data at t = 1, 2, 4, …. N is i.e Y = 1, 2, 4, …… N (i.e. skip the value at t = 3)

T (Time)Y (Known Data)

Calculation Result (using the method in the reference):

Estimation of Y at T=Tmax+1 :
Confidence Level of Estimation (%):