The research, which took into account data from 3,000 sets of twins in the UK, showed that those with more than 11 moles on one arm were at a higher risk of skin cancer or melanoma, whilst those with more than 100 moles all over their body were at five times the normal risk.
Counting the moles on the right arm was found to be a helpful indicator of the total number of moles an individual may have - the women in the study with more than seven moles in this area had nine times the risk of having more than 50 on their whole body.
Those with more than 11 on their right arm were more likely to have more than 100 on their body in total, meaning they were at a significantly higher risk of developing a melanoma.
Having more than 100 moles across the total body can be an indicator of a high risk of skin cancer
Lead author of the study, Simone Ribero of King's College London, explained: 'The findings could have a significant impact for primary care, allowing GPs to more accurately estimate the total number of moles in a patient extremely quickly via an easily accessible body part.'
However, Dr Claire Knight, health information manager at Cancer Research UK, said that whilst the study findings could be useful, less than half of melanomas develop from existing moles, and other areas should be taken into account.
'It's important to know what's normal for your skin and to tell your doctor about any change in the size, shape, colour or feel of a mole or a normal patch of skin,' she stated.
'And don't just look at your arms - melanoma can develop anywhere on the body, and is most common on the trunk in men and the legs in women.'
Over-exposure to UV light, which predominantly comes from the sun itself or sources like sunbeds, is one of the main contributing external risk factors for skin cancer, but the NHS also lists 'a family history of the condition' 'pale skin that burns easily' and 'a large number of moles or freckles' as areas that can also have an influence.
If you are worried about a mole on any area of your body, seek the advice of your GP immediately.