Many people were consuming much more than the recommended 5g daily intake, with most of the salt content hidden in the everyday foods we eat, the Stroke Foundation said.
It is calling for mandatory labelling standards, rather than the voluntary system in place now.
"The World Health Organisation (WHO) is calling for set benchmarks that advise the safe levels of salt within our food and we're failing miserably right now," Stroke Foundation national marketing and fundraising manager Jess Winchester said.
Processed food of all kinds contained salt, she said.
"It's everything we love, unfortunately. It's pies, pastries, sausages, processed meats, sweet cakes, even plant-based foods have hidden salt lurking inside."
Often the salt could not be tasted, and so was a "hidden killer", Winchester said.
"We just don't know what's in our packaged foods. The Health Star Rating system that we have at the moment is completely voluntary and it's just not working.
"There are a number of intended foods that are supposed to be included in the Health Star Rating and the target for that was 50 percent. And we're only looking at 30 percent. So, the public is just in the dark around how much salt is in their food."
It is mandatory for ingredients to be listed, she said, but the information was confusing.
"It's super complicated and it doesn't explain it very easily."
Under current regulations, processed food lists the amount of sodium included, she said.
"You have to convert the amount of sodium into salt to then understand how much salt you should be eating on a daily basis, it's incredibly complicated.
"We're calling for ... a labelling system that would show at a glance if something is low in salt, medium in salt, or high in salt."
New Zealand and Australia were "failing miserably" when it came to labelling the amount of salt in food, she said.
"We want two things, which is the mandatory benchmarks so the appropriate levels of salt in our foods, we want that to be committed to by the New Zealand government, and we also want them to make it mandatory for that Health Star Rating System to appear on all the food products so that the public can make a really informed choice about what they're consuming."
