Portokalk is a calculator that calculates postage based on Posten Norge AS's criteria for sending letters. Portokalk Calculates the weight of the letter, or you can manually enter the weight of the letter. Portokalk shows postage for letters in domestic, europe and the world, for different thicknesses and formats on the letter. You also get the price if you choose to send recommended, value, or collection.

Portokalk also calculates the letters weight based on number of pages and paper type.