I just got a job offer to work in Denmark, the contract says: "DKR 37500", however I'm not sure if that is the net amount of money, most likely not and I should deduct the taxes. Didn't contact them yet, wanted to know if it's a common practice to write down the salary amount without adding any extra details.
In most places in the world it is usual to quote salaries as gross (i.e. before any taxes or social security payments), simply because everyone's tax situation could potentially be very different.
You can estimate the amount of tax you would be required to pay by looking at the tax rates, and also see if there are any other deductions that will be taken.
Often there will be a 'pay as you earn'-type scheme, where the taxes etc. will be taken out at source, and then any discrepancies between the amount paid and the amount required to be paid will be made up at the end of the tax year.
I've worked in a few EU countries, and in all of them common practice is to display your gross salary, either monthly, or yearly. When paying they will deduct the taxes you have to pay, and only pay you the rest. (This usually only applies for workers, and not contractors or self-employed people)
If you are unsure about the local taxes salary calculator websites are usually available (although I couldn't find a good one for Denmark yet), where you can enter your weekly/monthly/yearly salary, some of your additional details, and it will tell you how much will be deducted from your paycheck (or how much you'll have to pay). The actual amount you have to tax might be different though, especially if you start working in the middle of the tax year, which you usually get back (or have to pay in addition) at the end of the tax year when doing the tax returns.