# Form calculation widget: Log() function is named incorrectly

**mbewley**I've written this Navy Circumference Formula exactly as its written in Excel and can't get it to work/calculate properly in JotForm. I need assistance with correcting this formula -- what am I missing/doing wrong?

- JotForm Support
**Kiran**I see that the form is showing some calculated result as I enter some values to it. However, I am not sure if it is calculating correctly. If you can provide us with the formula that you are working on, we can take a look and examine the form calculation.

We will wait for your response. Thank you!

- JotForm Support
**EltonCris**That's one pretty complex calculation. :)

Anyway, my suggestion is to break down the formula. This is to ensure that you are getting the right number on every calculation.

Example:

1. First calculation field gets the

*%Fat*value2. Second calculation gets the

*log(abdomen-neck)*3. Third gets the

*log(height)*And then on your final calculation, you simply use the value on each of these fields and then calculation them. This at least simplifies the calculation process and probably gives a finer result.

Please try it and let us know if we can be of further help.

**mbewley**Thanks for everyone’s assistance. I tried your suggestion Elton Cris but your suggestion didn't seem to work. In fact, the problem appears to be with the log equation — it simply doesn’t work.

Suggestions welcomed.

Regards,

Bewley

...- JotForm Support
**Kiran**Could you share the form URL that you have already worked with Elton's suggestion so that we may be able to fix it? Also, if you can provide us the Excel sheet with the formula we can check that might help us. You may email the Excel sheet to support@jotform.com with the subject title "Support forum - 1271671".

Thanks!

**mbewley**Thanks for your help Kiran. I already scraped the "Elton's" form since it didn't work. I've included all the excel formulas in this thread but will upload the excel sheet per your instructions.

A simple test for the JotForm log function is create a field and enter a value. Next, create a calculating field with log function and no calculations happen in JotForm. I do the same in Excel and it works, which led me to state in my previous post the log JotForm function doesn't work.

Your assistance is greatly appreciated.

- JotForm Support
**Kiran**Thank you for sharing the spreadsheet with us. Please allow me some time to work on the form and see if I can get you something. I'll update you here once I have any news in this regard.

Thank you!

**mbewley**Thank you very much, Kiran for your time and willingness to assist. Greatly appreciated!!!

- JotForm Support
**Kiran**Thank you for your patience. As I tried to create the form to use the same formula, I notice that the log() value is being calculated incorrectly which is why the calculation is failing on the form.

Here is the form that I was trying to create: https://form.jotform.com/72983631607968

I am forwarding the issue to our backend team to take a look at it. Once we have any update from them, I'll update the form and let you know here.

Thank you!

**mbewley**I knew I wasn't crazy when I said the log() function didn't seem to work ;-)

Thank you, Kiran for your all your time and assistance -- much appreciated!!!

Regards,

Mike

**mbewley**Kiran, has anyone figured out the problem to the log() function?

- JotForm Support
**Victoria_K**Hello,

I was checking the log() function of

**Form Calculation**widget and it seems that function calculates properly. Although, it's naming on the list is confusing (I would name it "**ln**" as it is using base of "**e**"), the description is much more informative:This way, I can suggest to calculate a logarithm base 10 with the following formula:

LN10 is also available on the list of functions.

It can be also of help to look through math functions descriptions at our guide:

**Form-Calculation-Math-Function-Reference**Here is my test form: https://form.jotform.com/81276327384967

Please check if it solves your question and let us know if you need further assistance.

Thank you.

- JotForm Support
**Victoria_K**Hello Mike,

I have checked the function and it's behaviour first. Then I tested to see if I get same results in excel and Form Calculation widget using parts of your formula. The log() produces same results with the formula I provided, so it should work for larger calculations as well:

As I was not sure if you still need to perform the same calculation, I have not re-created the steps of this thread. But, if you provide us a link to the form you're currently working on, we can assist.

Get back to us if needed.

Thank you!

- JotForm Support
**Victoria_K**It seems that you have updated your previous question with

*"I'm not sure how you can apply LAN10 to a Log() function?"*LOG(number) = LN(number) / LN10, where LN(number) is the function currently available at Form Calculations widget as log().

Can you provide the link to your form, so I could be more explicit?

**mbewley**Here is a link to the form. Understand, this form has IF statements for male vs female and whether user knows their body fat percentage or not. So, in order for a MALE USER who DOES NOT know their body fat, field options appear and calculations for body fat are appropriated.

https://www.jotform.com/build/72976472994174?iak=0dc12d28c679dda6f30ca96d9bad0c6d-2e675f44c1940d9f

Are you suggesting LAN10 is comparable to LOG10 (10 being a sub)

MALE

FEMALE

- JotForm Support
**Victoria_K**Hello again,

I am testing the formula you have shared. Unfortunately, I do not have any results yet, but I am sure that the issue with log() function is resolved. As I suppose there is another incorrectness with Form Calculations widget, I have moved your formula as new thread. I will get back to you soon with the results of my tests here: https://www.jotform.com/answers/1468338