MERs, or management expense ratios, are cost ratios calculated to a standard formula by all fund managers to give investors a comparable standard by which to compare the ongoing fees on funds.

The formula combines fees like management investment fees, commissions to advisers, manager administration expenses etc. and expresses them as one simple percentage rate.

Multiply the MER quoted for a fund by the amount of capital you have to invest to get an idea of the annual fee the fund manager will charge.