# Percentage conversion

Six Sigma – iSixSigma Forums Old Forums General Percentage conversion

Viewing 9 posts - 1 through 9 (of 9 total)
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• #66976

“Ken”
Participant

John,

Do you desire to convert a process yield value or percent defective into a Sigma value?

Ken

0
#66977

Gary Cone
Participant

John,

There are tables published for this in almost everything writen by Mikel
Harry or Motorola. If you do not have easy access to these, you can use a
normal table to get the same. The conversion is to get the z value from the
table and add 1.5. For example, if you are at 1350 defects per million
opportunities, the corresponding z value is 3, add 1.5 for a sigma value of
4.5. The 1.5 is the infamous 1.5 sigma shift.

Gary Cone

0
#27389

Participant

Is there anyway to convert percentages alone into sigma ratings, or is there a chart avilable somewhere?
Thanks everyone….John

0
#66986

Praneet
Participant

Hi John
There are tables available on the internet which will help you out with finding out your Sigma value from Percentage. However I would like to share a ready reckoner which I use. Hope you find this useful

% age DPMO Sigma
69.15 308537 2
93.33 66807 3
99.38 6210 4
99.97 233 5
99.993 3.4 6

Regards

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#66989

Participant

I am looking for a percent defective into a sigma value. Do you know where on the internet that a table may exist to print out? Thanks for all your help.

0
#66990

Participant

Thanks for the help! I already have several chrts and tables but I cant seem to be able to find one from a percent to sigma.( Such as 99.9999, 99.9998, etc….)much like the general sigma conversion tables for errors per 10,000 or per million. Thanks agian ! John

0
#66993

Mendoza
Member

You could try to make a table in Excel, using the NORMSINV function.

DPMO = 1 – Percentage
Sigma = -NORMSINV(DPMO) + 1.5

You have to select diferent cells, like any other function in Excel, I only was trying to explain the equations you have to do in Excel.

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#66994

Gary Cone
Participant

The first forty values:

99.9992 5.821336746
99.9991 5.784083843
99.999 5.765457392
99.9989 5.74683094
99.9988 5.728204489
99.9987 5.709578037
99.9986 5.690951586
99.9985 5.672325134
99.9984 5.663011909
99.9983 5.644385457
99.9982 5.635072231
99.9981 5.61644578
99.998 5.607132554
99.9979 5.597819328
99.9978 5.588506103
99.9977 5.574536264
99.9976 5.565223038
99.9975 5.555909812
99.9974 5.546596587
99.9973 5.537283361
99.9972 5.527970135
99.9971 5.523313522
99.997 5.514000297
99.9969 5.504687071
99.9968 5.497702152
99.9967 5.490717232
99.9966 5.481404006
99.9965 5.476747394
99.9964 5.469762474
99.9963 5.462777555
99.9962 5.458120942
99.9961 5.448807716
99.996 5.444151103

Use the NORMSINV function in Excel as suggested.

0
#67038

John Venegas
Participant

Thanks for the help! I now have the right idea…..your help is greatly appriciated.

John

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