About 90 per cent of women are thought to get the wrong dose of drugs that are used to stimulate the ovaries into producing eggs.
Heavy doses of drugs cut the chances of conception, as they lead to the production of too many eggs of reduced quality. High drug doses also increase the risk of potentially life-threatening side effects, besides costing a lot of money.
The Consort Calculator offers "bespoke" treatment by ensuring that women receive drugs customised to their individual needs, based on age, weight, egg-producing potential and blood hormone levels.
The dose calculator was tried out by 161 women in an international study, led by Dr. Geoffrey Trew of Hammersmith Hospital in West London.
The researchers found that 75 per cent of the volunteers should get a lower dose than they would normally receive, while 15 per cent should get a higher dose.
When 113 of the women got the right dose, an average of ten eggs were collected. The pregnancy rate was 41.6 per cent, slightly higher than would have been expected.
"Ten eggs is ideal. The problem with getting too high doses of drugs is that they can lead to 16-18 eggs of poor quality, which when fertilised lead to poor quality embryos," the Daily Mail Quoted Dr Trew as saying.
He said that the calculator would be made available to NHS and private clinics worldwide from next month free of charge.
The programme has been developed for women aged 35 and under, but a separate one will be created for over-35s.