Age UK research predicts that the number of over 60s in the world will rise from 931 million today to 1.4 billion by 2030.
Nearly a quarter of all people on the planet will be aged 65 or older by 2040, its research adds.
The demographic trend creates enormous opportunities for global care home operators, but also considerable pressure on health and care systems, the charity suggests.
Age UK says many older people are able to stay fit, active and cognitively alert but some are at risk of becoming vulnerable.
It found that 4.5 million of those over the age of 65 are not online, while 300,000 rely on someone else to help them with their banking services, putting them at risk of becoming isolated and heavily reliant on traditional methods.
The results of the Age UK study were revealed at a conference debating financial services for the elderly at which Caroline Abrahams, charity director of Age UK, said: “We need to ask if the financial services sector is ready for the growth of the older population and if these services really work for people experiencing cognitive decline. It is vital that we develop age friendly financial services – which are an essential part of daily living.”