Calculator for product prices

I need a simple type of calculator that my customer can click one of 3 choices to determine the cost of their choice on a form. I've looked at some of the widgets but I don't understand the code.

You can use the Form Calculation widget in order to calculate the the value of the fields. Please check this demo form: https://form.jotform.com/70614783770966. You can clone it if you like.

Here's a guide on how I created that demo form:

1. Insert a "Single Choice" fields in the form.

2. After that, I assigned a calculation value of reach item in the Single Choice field. Just click the field and then click the "Properties" button. Go to "" and enter the values separated by line break.

3. After that, please insert a Form Calculation widget.

4. The formula that you'll use the "Size Field" + "Color Field". You can click the "Add Field" button and select the fields. The operator (+, -, x, /) is at the right side.

Here's the result:

Please check these guides:
How-to-Assign-Calculation-Value
Perform-Form-Calculation-Using-a-Widget

Hope that helps. Thank you.