The estimated direct cost of the resource super profits tax (RSPT) to superannuation members is surprisingly low, according to Industry Super Network (ISN).

The umbrella organisation for industry superannuation funds used analysis from Chant West, Standard & Poor's and the Australian Securities Exchange.

ISN concluded the effect of the RSPT on a person's balance of $50,000 amounts to "a variation of $57 on their fund balance".

"Such an impact is within the normal volatility of equities," the ISN statement said.

The direct costs to super fund members of the RSPT are also offset by a number of benefits, according to ISN.

In particular, the cost to super fund members would be offset by increased government services that would be funded by the resources tax, lower personal taxes, lower cost of goods due to lower corporate taxes, and increased super returns due to increased after-tax corporate profits as a result of reduced corporate taxes.

The analysis follows the announcement by five industry groups calling for bipartisan support for proposed changes to superannuation announced by Treasurer Wayne Swan last week.

The Association of Superannuation Funds of Australia, the Australian Institute of Superannuation Trustees, the Investment and Financial Services Association, ISN and the Self-Managed Superannuation Fund Professionals' Association of Australia have warned the opposition that millions of Australians will be threatened with less than adequate retirement savings if the changes are opposed.

The proposed changes included boosting the superannuation guarantee to 12 per cent and top-up arrangements for people over the age of 50.

"These landmark reforms will see super accounts boosted for average workers by $110,000 and aggregate national retirement savings up by half a trillion dollars," a joint statement by the five bodies said.