You take the NAV of the starting date, and the latest NAV and then calculate the return.
Returns = 100 * (NAV2/NAV1 – 1)
If you invest in regular plans, then the returns will be about 1% or so lesser than Direct Plans. This is because the latter carry ZERO commission. Over time this difference compounds to a huge difference of about 40% or more.
Go with an advisor who offers only direct plans, not just for the zero commission but also because you get honest advice. No peddling of funds that carry higher commission.