Calculating the cost per service

There are several ways to do this, but as one of these requires the use of a scientific weight scale accurate to 0.01 of a gram, I will describe a method that anyone can do with kitchen scales and some sticky labels. I will use gel polish as the example, but you can use the same method for any material.  

Gel polish cost of service

The products used might include:

• Dehydrator
• Primer / Bonder
• Base gel polish
• Colour gel polish
• Top gel polish

Measurement

1. Weigh each of the products. 
2. Write the weight on a label and attach to each product
3. Each time you use the product, mark the label so you are counting the number of uses
4. After 10 uses, weight the product again and write this on the label.

Calculation

• Amount used per service = (original weight – 10 uses weight) / 10                        
• Number of services per product = weight of product when new / amount used per service
• Cost of product per service = Price of product / Number of services per product  
• Once you have done this for each of the products used, simple add up the costs for each of the products used. That gives you the total cost per service.  

Note

This does not include sanitiser liquid, wipe-off liquid, nail files, nitrile gloves, etc.  You can add these to the calculation. 

For the purpose of this simple method, we are assuming 1ml = 1gram i.e. 15ml of gel polish weighs 15 grams. This assumption is only true for water. Gels and gel polish usually weigh more, perhaps 1ml might weight between 1.1 and 1.3 grams. Liquids also vary in weight.