The 63-year-old, who is worth around £73 billion ($96.5 billion), said he and other business barons should have to contribute more.
In an interview with the Mail, he said: ‘I have paid more than $10billion (£7.75billion) in taxes but I should have paid more. I more than followed the law but I think things should be more progressive.’
The father of three made his fortune after founding Microsoft in 1975. It is now one of the world’s most valuable companies.
Mr Gates, who stepped back from his day-to-day role in 2008, is one of a handful of billionaires who have promised to leave most of their fortunes to good causes rather than to their children.
With his 54-year-old wife he runs the Bill & Melinda Gates Foundation, which is dedicated to tackling poverty and disease in poorer countries.
‘I don’t deserve my fortune,’ Mr Gates added. ‘Nobody does. It has come through timing, luck, and through people I worked with. I certainly worked hard and I think software has been a beneficial thing, but I benefited from a structure too.
‘I don’t think giving the money to my children would be good for them or good for society.
‘So after whatever consumption I have, and after some left aside for the kids and for taxes, the rest of the money goes to the foundation.
‘Melinda and I work hard all the time to make sure that money goes to help those most in need.’
He said he was in favour of raising inheritance tax. In the US, parents can leave almost £9million to their heirs without being subject to tax.
Mr Gates also supported calls for more clarity about the taxes paid by technology giants so it is easier to see whether the amounts handed over are fair.
‘I’m a big fan of transparency,’ he said. ‘In terms of corporate tax, if people want to collect more from different types of companies then we need to change the law.’
His comments came as he and his wife published their annual letter setting out their main concerns about the world. They highlighted how nationalism was endangering global co-operation on important health issues.
The couple were first spurred into philanthropy after reading in a newspaper about hundreds of thousands of children dying of diarrhoea in poor parts of the world. Since then global health schemes – with help from governments and charities such as their foundation – have helped save millions of lives that would otherwise have been lost to diseases such as HIV, tuberculosis and malaria. Mr Gates claimed these schemes were under threat.
In his letter, he said: ‘I worry that wealthy countries are turning inward and will take such a limited view of their own self-interest that they’ll decide these efforts aren’t worth the cost.
‘Or that even if everyone agrees in principle that aid is important, they’ll be so polarized that their political allegiances will keep them from taking action.’
Mrs Gates added: ‘Strengthening health systems overseas decreases the chance of a deadly pathogen like ebola becoming a global epidemic.
‘And ensuring every parent everywhere has the opportunity to raise safe, educated, healthy kids makes it less likely they will embark on desperate journeys to seek better lives elsewhere.
‘There is nothing about putting your country first that requires turning your back on the rest of the world. If anything, the opposite is true.’
The UK Government teamed up with the Gates Foundation in 2016 to commit £3billion to fighting malaria.
Mr Gates said other organisations that would need further funding this year and next include the Global Fund to Fight AIDS, Tuberculosis and Malaria, and Gavi, which improves access to vaccines among children in poor countries. In their letter, the couple also called for the collection of better data on women’s lives in developing countries.
They also said action was needed to cut carbon emissions.