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Strange calculations in checkout

Strange calculations in checkout

Hello people, 


We have a little problem in our checkout.

Schermafbeelding 2017-08-24 om 10.22.01.png

We are testing our Paypal implementation and for Paypal orders we want to add a surcharge (3%).

The surcharge should be calculated over the subtotal.


The situation

The subtotal: €549,10

Surcharge: €24,12


€549,10 / 100 * 3 = €16,47

The surcharge should be €16,47 but it is €24,12


What it should be

Subtotal: 549,10

Surcharge: €549,10 / 100 * 3 = €16,47

VAT: €549,10 + €16,47 = €565,57

Our shop is in the Netherlands, so the tax rate is 21%

€565,57 * 1,21 = €684,34


The other problem

When I was writing this article, I came across another problem. Behind the 4 products, you see another amount. This is the amount including tax. If you add up the amounts behind the products, you get: €532,88 + €23,24 + €90,14 + €18,15 = €664,41

€664,41 / 121 * 100 = €549,10. This means those amounts are including tax. This might confuse customers. Is there any way I can display those prices EX tax?



Anyone knows what the problem might be to those problems?


Thanks in advance!









Re: Strange calculations in checkout

Hmm, that is strange.


Would you be able to share your configuration settings for tax calculation and the paypal surcharge please?


I can get to the 24.12 surcharge amount if tax at 21% is applied twice to the 3% surcharge so that could be where this is going wrong. 

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