I Need A Basic Calculator Built And Designed To Be Added To Shopify Theme

THIS IS FOR A DESIGN AND INSTALL Hello, I need a calculator built and designed that will need to be added to part of my theme so that it appears on every product page. This is on Shopify and the Theme is - Loft Calculator will be very basic and involve the following "text" - How Many Boxes Do I Need Then a box that people can click that says length of wall in meters - when they click this they can then enter the width of wall in number for example 2 (need to be to 2 decimal placed) Then it will have a X - for multiply Then a box that people can click that says height of wall in meters - when they click this they can then enter the height of wall in number for example 2 (need to be to 2 decimal placed) Then a button that says "calculate" It needs to multiply the width and height together then multiply it by two - for example using the above calculation 2 x 2 is 4 this will then need to be multiplied by 2 so when they click calculate it would show as 8. Then a button underneath that says "Add 15% for Wastage?" If they select this then it will add 15% on to the result rounded to the nearest whole number.