The UK's GDP could have been almost £100bn higher in 2010 had British society been fairer in the preceding decades, according to Nicola Sturgeon.
The First Minister of Scotland said her government, which analysed data from the Organisation for Economic Co-operation and Development (OECD), found that the staggering figures equate to around £1,600 ($2,458, €2,197) per head.
The Scottish National Party (SNP) leader is expected to argue that a more equal society will also generate more prosperity.
Sturgeon will also unveil the Scottish Government's economic plan ahead of the forthcoming general election.
"Our economic strategy will set out a long term vision based on one fundamental principle: by becoming a fairer society, we will also become a more productive and more prosperous society," the SNP leader will say.
"We want to see economic growth that is inclusive, innovative and fairly distributed. For too long, our economy has been held back by rising inequality as a result of successive generations of Westminster economic policy.
"I have been clear that a key priority for this government is to tackle the blight of inequality, which serves as a destructive social and economic spiral.
"These figures suggest that had equality and economic growth been confronted with equal importance, then UK GDP would now be approximately £100bn higher. That is a proposition that simply cannot be ignored.
"That failure of Westminster's economic policy to properly address inequality - and the resultant loss to economic growth - has merely been compounded by the more recent austerity policies pursued by the UK government and which the Scottish government is deeply opposed to.
"We are using every lever and platform at our disposal to mitigate the effects of austerity."
Scottish Labour attacked Sturgeon and the SNP for the "appalling" inequality in Scotland.
"Sturgeon is right to point out the appalling inequality in Scotland after five years of the Tories and eight years of the SNP in power," said Jackie Baillie MSP, Scottish Labour's finance spokeswoman.
"Scottish Labour has a plan to make Scotland the fairest nation on earth. We will make work pay for all Scots by calling time on zero hours contracts, using the mansion tax to invest in our NHS and raising the minimum wage for those in work.
"We have also set out how we would close the attainment gap by investing £125m to support working class kids who have been left behind by the SNP Government in Edinburgh.
"That's a powerful vision for making Scotland a better and fairer country."