Compute Promoters Needed to Meet Net Promoter Score (NPS)

[Venus Uson]

Hello,

I need help in deriving the formula to get the total number of promoters needed in order for us to meet our NPS.

Actual Survey Count: 3699
Promoters: 2903
Neutrals: 261
Detractors: 535
Net Promoter Score (NPS): 64.02
Formula = ((Promoters - Detractors)/(Promoters + Neutrals + Detractors)*100)

I need to know the formula on how to get the total number of promoters needed in order for our 64.02 NPS to be at 80.00.

Date	Promoters	Neutral	Detractors	# of Survey	NPS	Target	Cumulative	% to Goal
1-Jan	178	15	38	231	60.61	80	60.61	75.76%
2-Jan	219	24	42	285	62.11	80	61.43	76.79%
3-Jan	216	21	48	285	58.95	80	60.55	75.69%
4-Jan	0	0	0	0		80	60.55	75.69%
5-Jan	344	24	69	437	62.93	80	61.39	76.74%
6-Jan	228	19	48	295	61.02	80	61.32	76.65%
7-Jan	220	22	38	280	65.00	80	61.89	77.36%
8-Jan	134	11	23	168	66.07	80	62.24	77.80%
9-Jan	191	22	41	254	59.06	80	61.88	77.35%
10-Jan	198	19	33	250	66.00	80	62.29	77.87%
11-Jan	313	24	52	389	67.10	80	62.94	78.68%
12-Jan	250	17	47	314	64.65	80	63.11	78.89%
13-Jan	210	22	33	265	66.79	80	63.39	79.24%
14-Jan	202	21	23	246	72.76	80	64.02	80.02%
15-Jan	0	0	0	0		80	64.02	80.02%
16-Jan				0		80	64.02	80.02%
17-Jan				0		80	64.02	80.02%
18-Jan				0		80	64.02	80.02%
19-Jan				0		80	64.02	80.02%
20-Jan				0		80	64.02	80.02%
21-Jan				0		80	64.02	80.02%
22-Jan				0		80	64.02	80.02%
23-Jan				0		80	64.02	80.02%
24-Jan				0		80	64.02	80.02%
25-Jan				0		80	64.02	80.02%
26-Jan				0		80	64.02	80.02%
27-Jan				0		80	64.02	80.02%
28-Jan				0		80	64.02	80.02%
29-Jan				0		80	64.02	80.02%
30-Jan				0		80	64.02	80.02%
31-Jan				0		80	64.02	80.02%
Grand Total	2903	261	535	3699	64.02

 

[alansidman]

Using the Solver, the answer is 5859.0075

Book2
	A	B	C	D	E	F
34	Grand Total	5859.0075	261	535	3699	80.0000225
Sheet1

Cell Formulas
Range	Formula
F34	F34	=(B34-D34)/(B34+C34+D34)*100

Named Ranges
Name	Refers To	Cells
solver_adj	=Sheet1!$B$34	F34