New economic modelling shows the cost of dementia will reach more than $1 trillion by 2056.

The government must develop a national dementia strategy because Australians are scared of the insidious disease costing billions, the president of Alzheimer's Australia says.

Each day in Australia, 244 people are diagnosed with dementia.

Without a cure, this is expected to increase to 328 people each day in 2026, and a staggering 653 people a day in 2056.

Apart from the human cost, new economic modelling shows the burden on the health system will be massive.

A report conducted by the National Centre for Social and Economic Modelling (NATSEM), released on Wednesday, estimates dementia to cost almost $15 billion in 2017, more than double the figure in 2002.

This is projected to skyrocket to $1.033 trillion during the next four decades.

The report also shows just a five per cent reduction in the number of people developing dementia over the age of 65 could lead to savings of $120.4 billion by 2056.

Alzheimer's Australia National president Graeme Samuel says the figures are a big wake-up call.

He wants a government funded National Dementia Strategy to deal with the issue, along with a focus on early diagnosis and prevention and risk reduction measures.

"The time for action is now. If we don't do something now, the cost is going to continue to grow to unsustainable levels," Professor Samuel said.

Canberra couple Dawn and Glyn McKay have welcomed calls for improvements to dementia care and support.

Mr McKay was diagnosed with vascular dementia six years ago and attends respite twice a week.

"It is so important for people with dementia to be able to continue to have social engagement," Mrs McKay said.

"People living with dementia need quality community, aged care and respite options."

Research "must" also be given priority.

"There is no cure or preventative process for dementia, there is no silver bullet," Prof Samuel said.

"People are scared. They're scared that it's going to happen to them," he told AAP.

"The two biggest worries for men over the age of 65 have been demonstrated now to be cancer and dementia. That's what they're worried about."