# How to calculate the cost automatically based on a fix value?

**rbmans**I have a product where one cost is based on a specific value stated by customer. I therefore wonder, would it be possible to have customer type a value, and have the form automatically calculate the cost based on a fixed value in percentage? I'll give you some examples.

Let's say that customer type 100 then I want the result/ cost to be calculated on 100 x 1.1% = 1.1. If customer types 2500, calculation should be 2500 x 1.1% = 27.5.If this is possible, I will replace the item "cost/ bonus".

- JotForm Support
**Richie_P**Hello rbmans,

Yes you can calculate fields and set the value using conditional logic.

Here is a screen shot.

To achieve this, in your build view go to settings then conditions

Click the + add sign and choose UPDATE/CALCULATED FIELD

In your IF "select the field where your customer inputs his value" in my case its Value then STATE to Is Filled.

Do: Calculate a field's value then ADD FIELD, select the field in your IF then add your calculations. In you summery is where you want to put the output of your calculation.

.

Here is the link to my form, feel free to clone it : https://form.jotform.com/73233569416965

Please let us know if we can be of further assistance.

Best Regards. **rbmans**Thanks!

Took some time to realise that I can't use normal math and %. But using your formula it works.A bit curious of why it doesn't work though...

cheers

- JotForm Support
**Kiran**You may also use a form calculation widget to perform calculations on the form without using any conditions. For the provided example, you may set up the formula as shown in the screenshot below:

Please refer to the guide below that can help you with using the form calculation widget.

https://www.jotform.com/help/259-How-to-Perform-Form-Calculation-Using-a-Widget

Please get back to us if you need any further assistance. We will be happy to help.

**rbmans**Thanks, it does work with conditions as well. But only when using formula from above.

Therefore I am A bit curious of why it doesn't work utilizing normal math or % though...- JotForm Support
**Jim_R**I think what you're referring to is the normal percentage calculation.

*e.g.**25% of 3000 = 750**10% of 18 = 1.8*I don't think there's a way to calculate the percentage mathematically without converting it to fraction or decimal first. When solving for percentage,

**1.1% of X**equates to**X * 0.011**. So you need to either use fractions as demonstrated on the examples given by my colleagues or go straight to using decimal by dividing the percent% value by 100.*e.g.**Use***X * 0.011**instead of**X * (1.1 / 100)** **rbmans**Thanks for response but I was probably not clear enough. What I meant was that it is not possible to

*Use X * 0.011*- JotForm Support
**jonathan**I am not sure how you meant it was not possible... because using the Form Calculation widget as mentioned already should work for calculation like

*X * 0.011*Example: https://form.jotform.com/73236666263966

I hope this help. Let us know if you need further assistance.

**rbmans**ok, actually it does not matter since it works with the formula sen before. Maybe I have to use the widget. I don't do that,. Only the condition settings.

Any way thanks.

- JotForm Support
**Kevin_G**Please note that the conditions wizard for calculations is similar to the calculation widget wizard so you can do the same too.

Here is a guide about it: https://www.jotform.com/help/268-How-to-Insert-Text-or-Calculation-into-a-Field-Using-Conditional-Logic

I hope this helps.